6 Weeks Pregnant: Baby Development, Symptoms & What to Expect

What Is Happening With Your Baby at 6 Weeks?

At 6 weeks pregnant, your baby (embryo) is about 4-6 millimeters long – roughly the size of a lentil. The heart has started beating for the first time, the neural tube is closing to form the brain and spinal cord, and early facial features are beginning to form. The embryo now has a curved, tadpole-like shape with a head and tail end.

Week 6 marks a period of extraordinarily rapid development for your growing baby. At this stage, your baby is officially called an embryo and will remain so until the end of week 10, when it becomes a fetus. The embryo has grown from a tiny ball of cells into a recognizable form with distinct features beginning to emerge. This is one of the most critical periods of development, as the foundation for every major organ system is being established.

The embryo is now composed of three distinct layers of cells, each destined to become different parts of the body. The ectoderm (outer layer) will develop into the nervous system, skin, hair, and nails. The mesoderm (middle layer) forms the heart, blood vessels, muscles, and bones. The endoderm (inner layer) becomes the digestive system, lungs, and other internal organs.

During week 6, blood is beginning to circulate through the embryo's tiny body. The circulatory system is one of the first to develop because the growing embryo needs a way to receive nutrients and oxygen. Small blood vessels are forming, connecting to what will become the placenta – the vital organ that will nourish your baby throughout pregnancy.

The Heart Begins to Beat

One of the most remarkable developments at 6 weeks is that the embryonic heart starts beating. The heart began as a simple tube around day 22-23 after conception and has now developed into a primitive organ that can pump blood. At this stage, the heart rate is typically between 90-110 beats per minute, though it will increase to 140-170 bpm by week 9.

The heartbeat may be visible on a transvaginal ultrasound during week 6, though it's not always detectable this early. If no heartbeat is seen at 6 weeks, it doesn't necessarily indicate a problem – the timing of conception may be slightly different than calculated, or it may simply be too early. Healthcare providers typically recommend a follow-up scan in one to two weeks if the heartbeat isn't visible initially.

The heart will continue to develop over the coming weeks, eventually forming four chambers and becoming the complex organ that will beat over 100,000 times per day throughout your child's life. Hearing or seeing your baby's heartbeat for the first time is often an emotional milestone for expectant parents.

Neural Tube Development

The neural tube, which will become your baby's brain and spinal cord, is closing during week 6. This is a critical process that typically completes around the end of this week. The neural tube forms from the ectoderm layer and is the earliest structure of the central nervous system.

Adequate folic acid intake is crucial during this time to help prevent neural tube defects such as spina bifida and anencephaly. These conditions occur when the neural tube fails to close completely. This is why healthcare providers recommend that all women of childbearing age take 400-800 micrograms of folic acid daily – ideally beginning at least one month before conception.

Already, the brain is beginning to divide into its major regions: the forebrain, midbrain, and hindbrain. These will eventually control everything from thought and emotion to breathing and heart rate. The development happening right now will influence your child's neurological function for their entire life.

Early Facial Features

Even at this early stage, the foundations for your baby's face are being laid. Small depressions on the sides of the head mark where the eyes will form. These are called optic pits and will eventually develop into the complex structures needed for vision. The retina – the light-sensitive tissue at the back of the eye – is already beginning to form.

The ears are also starting to develop as small folds of tissue on each side of the head. While they won't be functional for many weeks, the intricate structures of the inner, middle, and outer ear are beginning their formation. Similarly, small indentations mark the future locations of the nostrils, and a primitive mouth opening is visible.

The jaw and pharyngeal arches are developing – these will eventually form the jaw, throat, and other structures of the lower face. By the end of the first trimester, your baby will have recognizable facial features, but the groundwork is being laid right now.

Limb Buds Appear

Small paddle-shaped limb buds are beginning to emerge from the embryo's body. These are the earliest signs of arms and legs. During week 6, the arm buds are slightly more developed than the leg buds, reflecting the head-to-toe pattern of embryonic development where structures closer to the head develop first.

Over the coming weeks, these limb buds will elongate, segment into upper and lower portions, and eventually develop fingers and toes. By week 8, the basic structure of the hands and feet will be visible, though the fingers and toes will still be webbed.

What Symptoms Are Common at 6 Weeks Pregnant?

Common symptoms at 6 weeks pregnant include morning sickness (nausea and vomiting), fatigue, breast tenderness and swelling, frequent urination, mood swings, food aversions, and heightened sense of smell. Symptoms vary greatly between individuals – some women have severe symptoms while others have none at all.

Week 6 often marks the beginning of noticeable pregnancy symptoms for many women. The surge in pregnancy hormones – particularly human chorionic gonadotropin (hCG), progesterone, and estrogen – is responsible for most of these symptoms. HCG levels are rising rapidly during this time, doubling approximately every 48-72 hours, which contributes to the intensity of early pregnancy symptoms.

It's important to understand that every pregnancy is unique. Some women experience significant symptoms from very early on, while others feel relatively normal throughout the first trimester. The presence or absence of symptoms does not indicate whether the pregnancy is progressing normally. If you have concerns about your symptoms – or lack thereof – discuss them with your healthcare provider for reassurance.

Morning Sickness

Morning sickness is one of the most well-known early pregnancy symptoms, affecting up to 80% of pregnant women. Despite its name, nausea and vomiting can occur at any time of day or night. Symptoms typically begin around week 6 and peak between weeks 8-12, then gradually improve for most women by the end of the first trimester.

The exact cause of morning sickness isn't fully understood, but rising hCG levels are thought to play a significant role. Other factors may include heightened sensitivity to odors, changes in the digestive system, and the body's response to the physical demands of early pregnancy.

To help manage morning sickness:

• Eat small, frequent meals rather than three large ones
• Keep plain crackers or dry toast by your bed to eat before getting up
• Avoid foods with strong smells that trigger nausea
• Stay hydrated by sipping water, ginger tea, or clear broths throughout the day
• Get plenty of rest – fatigue can worsen nausea
• Try ginger supplements or vitamin B6, which may help reduce nausea

Fatigue and Exhaustion

Overwhelming fatigue is extremely common at 6 weeks pregnant. Your body is working incredibly hard to support the developing pregnancy, even though you may not see visible changes yet. The hormone progesterone, which rises dramatically in early pregnancy, has a sedative effect that contributes to tiredness.

Additionally, your body is producing more blood to carry nutrients and oxygen to the embryo, your heart rate increases, and your metabolism is changing. All of these processes require energy, leaving you feeling exhausted. Many women find that they need significantly more sleep during the first trimester than at other times.

To manage fatigue:

• Listen to your body and rest when you need to
• Go to bed earlier and consider taking short naps
• Maintain regular, gentle exercise if your healthcare provider approves
• Eat a balanced diet rich in iron and protein
• Stay hydrated and limit caffeine (which can disrupt sleep)

Breast Changes

Your breasts are already preparing for their future role in nourishing your baby. Breast tenderness, swelling, and sensitivity are very common at 6 weeks. You may notice that your breasts feel heavier, fuller, or sore – similar to but often more intense than premenstrual breast changes.

The areolas (the darker area around the nipples) may begin to darken and enlarge. Small bumps on the areolas, called Montgomery tubercles, may become more prominent – these are oil glands that help keep the nipple moisturized. Some women also notice that the veins in their breasts become more visible as blood flow to the area increases.

Frequent Urination

Even though your uterus is still quite small, frequent urination is a common symptom at 6 weeks. This occurs because your blood volume is increasing, causing your kidneys to process more fluid that ends up in your bladder. Additionally, pregnancy hormones affect bladder function.

As pregnancy progresses, the growing uterus will put physical pressure on the bladder, further increasing urinary frequency. While frequent urination is normal, burning, pain, or blood in the urine could indicate a urinary tract infection, which requires treatment.

Mood Changes

Hormonal fluctuations can cause significant mood swings during early pregnancy. You may find yourself feeling happy one moment and tearful the next. Anxiety about the pregnancy, physical discomfort from other symptoms, and fatigue can all contribute to emotional changes.

It's important to distinguish between normal pregnancy mood swings and symptoms of depression or anxiety that might require professional support. If you're experiencing persistent feelings of sadness, hopelessness, or excessive worry that interferes with daily life, speak with your healthcare provider.

Food Aversions and Cravings

Many women develop strong aversions to certain foods or smells during early pregnancy. Foods you previously enjoyed may suddenly seem repulsive. Common aversions include coffee, meat, eggs, and spicy or fatty foods. This may be nature's way of protecting the developing embryo from potentially harmful substances.

Conversely, you may also experience cravings for specific foods. While the occasional indulgence is fine, try to maintain a balanced diet that provides the nutrients you and your baby need. If you're craving non-food items like ice, dirt, or chalk, contact your healthcare provider as this could indicate a nutritional deficiency.

What Changes Are Happening in Your Body?

At 6 weeks pregnant, your uterus is beginning to expand (though not yet visible externally), blood volume is increasing, and hormone levels are rising dramatically. You may experience bloating, mild cramping, constipation, and breast changes. While you likely don't look pregnant yet, significant changes are occurring internally to support the growing embryo.

Although you probably don't look pregnant at 6 weeks, your body is undergoing remarkable changes to support your developing baby. Understanding these changes can help you feel more connected to your pregnancy and recognize what's normal versus what might warrant a call to your healthcare provider.

Uterine Changes

Your uterus is beginning to grow, though the change isn't visible from the outside yet. Before pregnancy, the uterus is about the size and shape of a pear. By 6 weeks, it has grown slightly to accommodate the developing embryo. Some women notice a feeling of fullness or heaviness in the lower abdomen.

Mild cramping is common during early pregnancy as the uterus begins to stretch. These cramps often feel similar to menstrual cramps and are usually nothing to worry about. However, severe cramping, especially if accompanied by bleeding, should be evaluated by a healthcare provider.

Increased Blood Volume

Your body is producing more blood to nourish the pregnancy. By the end of pregnancy, your blood volume will increase by about 50%. This process begins early, which is why adequate iron intake is important from the start. The increased blood volume also contributes to fatigue as your heart works harder to circulate the additional blood.

Hormonal Changes

The hormones driving your pregnancy are at work around the clock. Human chorionic gonadotropin (hCG) is rising rapidly – this is the hormone detected by pregnancy tests. HCG helps maintain the corpus luteum, which produces progesterone to support the pregnancy until the placenta takes over around week 10-12.

Progesterone is essential for maintaining the uterine lining and preventing contractions that could dislodge the embryo. It also causes many pregnancy symptoms, including fatigue, breast tenderness, and constipation. Estrogen supports the development of the placenta and the baby's organs while also contributing to blood flow changes.

Digestive Changes

Bloating is very common at 6 weeks, even though there's no visible baby bump. Progesterone relaxes smooth muscle throughout the body, including the digestive tract, which slows digestion and can cause bloating and constipation. Many women find their pants feel tighter well before any actual weight gain.

To manage digestive symptoms:

• Eat plenty of fiber from fruits, vegetables, and whole grains
• Drink plenty of water throughout the day
• Exercise regularly if approved by your healthcare provider
• Eat smaller, more frequent meals

When Should You Schedule Your First Prenatal Appointment?

Most healthcare providers recommend scheduling your first prenatal appointment between weeks 8-10 of pregnancy. However, you should contact your healthcare provider as soon as you get a positive pregnancy test to establish care. If you have a high-risk pregnancy history or concerning symptoms, earlier evaluation may be recommended.

Prenatal care is one of the most important investments you can make in your baby's health and your own. Regular prenatal visits allow your healthcare provider to monitor the pregnancy, identify potential problems early, and provide guidance on maintaining a healthy pregnancy.

First Prenatal Visit

The first prenatal appointment is typically scheduled between 8-10 weeks of pregnancy. This timing allows for the embryo to be large enough for a meaningful ultrasound while still being early enough to address any concerns or risk factors. During this comprehensive visit, you can expect:

• Complete medical history review – including previous pregnancies, surgeries, chronic conditions, medications, and family medical history
• Physical examination – including blood pressure, weight, and possibly a pelvic exam
• Blood tests – checking blood type, Rh factor, complete blood count, immunity to certain infections, and screening for conditions like HIV and hepatitis
• Urine test – screening for urinary tract infections and checking protein and glucose levels
• Ultrasound – to confirm the pregnancy location, estimate gestational age, check for multiple pregnancies, and often detect the heartbeat
• Discussion of prenatal testing options – including screening tests and diagnostic tests for genetic conditions

What to Do Now at 6 Weeks

While your first appointment may not be for another few weeks, there's plenty you can do now to support a healthy pregnancy:

• Continue taking prenatal vitamins – especially those containing folic acid (400-800 mcg daily)
• Avoid alcohol, tobacco, and recreational drugs – these can cause serious harm to the developing embryo
• Limit caffeine – keep intake below 200 mg per day (about one 12-ounce cup of coffee)
• Eat a balanced diet – focus on fruits, vegetables, whole grains, lean proteins, and dairy
• Avoid certain foods – raw fish, undercooked meat, unpasteurized dairy, and high-mercury fish
• Check medications – consult your healthcare provider about any prescription or over-the-counter medications you take
• Stay active – gentle exercise is generally safe and beneficial during pregnancy

What Warning Signs Should You Watch For?

Contact your healthcare provider immediately if you experience heavy vaginal bleeding, severe abdominal or pelvic pain (especially on one side), dizziness or fainting, fever, or inability to keep any food or water down. These symptoms could indicate complications such as ectopic pregnancy, miscarriage, or severe morning sickness requiring treatment.

While most early pregnancies progress normally, it's important to know the warning signs that require medical attention. Early pregnancy is a time when certain complications, though uncommon, can occur. Being aware of concerning symptoms and seeking prompt care when needed can make a significant difference in outcomes.

Vaginal Bleeding

Light spotting is relatively common in early pregnancy and doesn't always indicate a problem. Up to 25% of pregnant women experience some bleeding during the first trimester, and many go on to have healthy pregnancies. Spotting can occur when the embryo implants into the uterine wall or due to increased sensitivity of the cervix.

However, you should contact your healthcare provider if you experience:

• Heavy bleeding (soaking a pad in an hour or less)
• Bleeding accompanied by cramping or pain
• Passing clots or tissue
• Persistent bleeding over several days

Severe Pain

Mild cramping is normal, but severe or sharp pain is not. Pay particular attention to pain that is:

• Concentrated on one side of the abdomen or pelvis
• Sharp, stabbing, or persistent
• Accompanied by dizziness, shoulder pain, or fainting
• Worsening over time

These symptoms could indicate an ectopic pregnancy – when the embryo implants outside the uterus, usually in a fallopian tube. Ectopic pregnancy is a medical emergency that requires immediate treatment.

What Lifestyle Changes Should You Make?

Key lifestyle changes at 6 weeks pregnant include taking prenatal vitamins with folic acid, avoiding alcohol and tobacco, limiting caffeine to under 200mg daily, eating a nutritious diet, avoiding raw/undercooked foods and high-mercury fish, staying physically active with safe exercises, getting adequate rest, and managing stress. Consult your healthcare provider before taking any medications.

The first trimester is a critical time for your baby's development, making healthy lifestyle choices particularly important. The choices you make now can have lasting effects on your baby's health. While this might feel overwhelming, remember that you don't need to be perfect – focus on making positive changes one step at a time.

Nutrition and Diet

A balanced, nutritious diet provides the building blocks for your baby's development. Focus on:

• Fruits and vegetables – aim for a variety of colors for different nutrients
• Whole grains – choose whole wheat bread, brown rice, and oatmeal
• Lean proteins – include chicken, fish (low-mercury varieties), beans, and eggs
• Dairy or calcium-rich alternatives – for bone development
• Healthy fats – from sources like avocados, nuts, and olive oil

Foods to avoid during pregnancy:

• Raw or undercooked meat, poultry, and eggs
• Raw fish and sushi
• High-mercury fish (shark, swordfish, king mackerel, tilefish)
• Unpasteurized milk and cheese
• Deli meats and hot dogs (unless heated until steaming)
• Unwashed fruits and vegetables

Exercise and Physical Activity

Regular exercise is generally safe and beneficial during pregnancy. Physical activity can help manage weight gain, improve mood, boost energy, and prepare your body for labor. Aim for about 30 minutes of moderate activity most days of the week.

Safe exercises during early pregnancy typically include:

• Walking
• Swimming
• Prenatal yoga or pilates
• Stationary cycling
• Low-impact aerobics

Avoid activities with high risk of falling or abdominal injury, contact sports, hot yoga or exercising in extreme heat, and lying flat on your back for extended periods (more relevant later in pregnancy).

Rest and Sleep

Your body needs extra rest during early pregnancy. The fatigue you're experiencing is real and serves a purpose – it's your body's way of telling you to slow down during this critical developmental period. Try to:

• Get 8-10 hours of sleep per night
• Take short naps during the day if needed
• Go to bed earlier than usual
• Rest when you feel tired rather than pushing through

How Can You Support Your Emotional Wellbeing?

Early pregnancy can be emotionally challenging with mood swings, anxiety about the pregnancy, and physical symptoms affecting your mental state. Support your emotional wellbeing by communicating openly with your partner and support system, practicing self-care, limiting stress when possible, and seeking professional help if you experience persistent depression or anxiety.

The emotional journey of early pregnancy is complex. Along with excitement and joy, you may experience worry, anxiety, mood swings, and a range of other feelings. These emotions are normal and shared by many expectant parents.

Common Emotional Experiences

Many women experience mixed emotions during early pregnancy:

• Anxiety about whether the pregnancy will progress normally
• Excitement about becoming a parent
• Worry about finances, career, or relationship changes
• Irritability due to hormonal fluctuations and physical symptoms
• Mood swings from happy to tearful without obvious cause

These feelings are all normal. The first trimester, when the risk of miscarriage is highest, can be particularly anxiety-provoking for many women. It's okay to feel cautiously optimistic rather than overwhelmingly excited.

Building Your Support System

Having emotional support during pregnancy is important for your wellbeing. Consider:

• Communicating openly with your partner about your feelings and concerns
• Connecting with friends or family members who can offer support
• Joining a prenatal class or pregnancy support group
• Speaking with your healthcare provider about emotional concerns

When to Seek Professional Help

While mood swings are normal, persistent feelings of depression or anxiety may require professional support. Contact your healthcare provider if you experience:

• Persistent sadness lasting more than two weeks
• Loss of interest in activities you usually enjoy
• Excessive worry that interferes with daily life
• Difficulty sleeping or sleeping too much
• Thoughts of harming yourself or the baby

Mental health support during pregnancy is important – conditions like prenatal depression and anxiety are treatable, and getting help benefits both you and your baby.