6 Weeks Pregnant: Symptoms, Scans, and Development
What's happening with your baby at 6 weeks pregnant, what symptoms to expect, and what you'll see at your first scan.
Key Takeaways
- Your embryo measures about 6mm — roughly the size of a pea or sweet pea
- The heart tube is beating at 90–110 beats per minute, and you may detect this on an early ultrasound
- Common symptoms include morning sickness, extreme fatigue, breast tenderness, and frequent urination
- Most women won't show a baby bump yet, though bloating can make your belly feel different
- An early scan at 6 weeks can confirm pregnancy location and check for a heartbeat
Six weeks pregnant hits differently. Maybe you've known for a couple of weeks, or maybe you only just took the test. Either way, this is usually when pregnancy starts feeling real — not just a positive line on a stick, but actual physical changes that your body is suddenly dealing with.
This week is when symptoms often ramp up. If you've been feeling relatively normal, that may change now. And if you're already struggling with nausea or exhaustion, know that you're not alone — this is one of the most intense weeks for early pregnancy symptoms.
Here's what to expect at 6 weeks: what's happening with your baby, what you might be feeling, and what happens at your first scan.
Your Baby at 6 Weeks
At 6 weeks, your baby — technically still called an embryo — is growing rapidly. Here's what's developed so far:
Size and appearance: Your embryo is about 6mm long, roughly the size and shape of a pea. It looks a bit like a tadpole, with a curved back and a small tail that's actually the beginning of the spine. The head is disproportionately large compared to the body, which is completely normal at this stage (NHS, 2024).
The heart: This is the big milestone. Your baby's heart isn't fully formed yet — it's still a heart tube rather than the four-chambered heart it will become — but cells in that tube are already beating. The heart rate at 6 weeks is typically 90–110 beats per minute, though there's a wide range of normal (American Pregnancy Association, 2023). If you have an early ultrasound this week, you may hear or see this heartbeat for the first time.
Limb buds: Tiny bumps are forming where arms and legs will eventually grow. They look more like little paddles than recognisable limbs right now, but the foundations are there.
Facial features: Dark spots mark where the eyes will form, and small indentations show where the ears and nose are beginning to develop.
Neural tube: The structure that will become the brain and spinal cord is closing. This is why folic acid supplementation in early pregnancy is so important — it reduces the risk of neural tube defects.
6 Weeks Pregnant Symptoms
If pregnancy symptoms were a dial, week 6 is often when someone turns it up. The hormones — particularly hCG (human chorionic gonadotropin) and progesterone — are rising rapidly, and your body is working hard to build the placenta that will support your baby for the rest of the pregnancy.
Common symptoms at 6 weeks:
Morning sickness. Despite the name, this can strike at any time of day — or all day. It's caused by rising hCG levels and affects up to 80% of pregnant women. For some, it's mild nausea. For others, it's vomiting multiple times a day. If you're being sick frequently, can't keep food or water down, or the nausea is severely impacting daily life, contact your midwife or GP — this could be hyperemesis gravidarum, which needs treatment (Tommy's, 2024).
Extreme fatigue. The exhaustion at 6 weeks can feel overwhelming. You're not just tired — you might feel like you could sleep for 12 hours and still need a nap. This is normal. Your body is building a placenta, supporting a rapidly growing embryo, and dealing with a huge hormonal shift. Rest when you can. This phase usually improves in the second trimester.
Breast tenderness. Your breasts may feel heavy, swollen, and incredibly sensitive. The areolas (the area around the nipples) may darken, and veins might become more visible. This is preparation for breastfeeding, driven by progesterone and oestrogen.
Frequent urination. You might already be making more trips to the bathroom. This is partly due to increased blood flow to your kidneys and partly because your growing uterus is starting to press on your bladder — even at 6 weeks, when the uterus is still quite small.
Mood swings. The hormonal rollercoaster affects your emotions too. You might cry at adverts, feel irrationally irritated, or swing between excitement and anxiety. This is normal, though exhausting.
Food aversions and cravings. Suddenly can't stand the smell of coffee? Desperate for foods you never usually eat? Taste and smell changes are common. Listen to your body — eat what you can tolerate.
Spotting and cramping. Light spotting and mild cramping can be normal at 6 weeks as the embryo implants more deeply and the uterus expands. However, heavy bleeding or severe pain needs immediate medical attention to rule out ectopic pregnancy or miscarriage.
Your 6-Week Pregnant Belly
At 6 weeks, you almost certainly won't look pregnant to anyone else. Your uterus is still tucked behind your pubic bone, and your baby is smaller than a fingernail.
But you might feel different. Bloating is common — progesterone slows digestion, which can leave you feeling gassy and swollen. Your clothes might feel tighter even though there's no baby bump yet.
Some women do notice a subtle change in their lower abdomen — a fullness or slight rounding. This is usually bloating rather than actual uterine growth, which becomes visible later.
If this isn't your first pregnancy, you might show earlier than you did before — your abdominal muscles have been stretched before, so they tend to relax sooner.
The 6-Week Ultrasound: What to Expect
Not everyone has a scan at 6 weeks. The NHS typically offers the first ultrasound between 8 and 14 weeks. But you might have an early scan if:
- You've had a previous ectopic pregnancy or miscarriage
- You've had fertility treatment
- You're experiencing pain or bleeding
- You've opted for a private early scan
What can you see at 6 weeks?
A transvaginal ultrasound (where the probe is inserted into the vagina) gives the clearest picture this early. An abdominal ultrasound may not show much yet.
The sonographer will look for:
- The gestational sac — a dark circle that contains the embryo
- The yolk sac — a small circle inside the gestational sac that provides nutrients until the placenta takes over
- The fetal pole — the early embryo itself, which should measure around 6mm
- A heartbeat — the cardiac activity flickering in the fetal pole. At 6 weeks, a heartbeat between 90–110 bpm is reassuring. Below 90 bpm may indicate a higher risk of miscarriage, though it's not definitive (Doubilet & Benson, Journal of Ultrasound in Medicine, 1995)
What if you don't see a heartbeat?
This is common at 6 weeks and doesn't automatically mean something is wrong. The timing might be slightly off — you may have ovulated later than you thought. Most sonographers will recommend a follow-up scan in 7–10 days to check for development.
Seeing no embryo in the gestational sac (called a "blighted ovum" or anembryonic pregnancy) or no gestational sac at all with positive pregnancy tests requires further investigation to rule out ectopic pregnancy.
What to Do This Week
Book your first midwife appointment. If you haven't already, contact your GP or local maternity services to book your "booking appointment." This usually happens between 8 and 10 weeks, but the sooner you get on the list, the better.
Continue folic acid. Keep taking 400 micrograms daily until at least the end of the first trimester. This reduces the risk of neural tube defects.
Consider vitamin D. The NHS recommends 10 micrograms of vitamin D daily throughout pregnancy and breastfeeding.
Eat what you can. If morning sickness is making balanced meals impossible, don't stress. Eat small, frequent snacks. Bland foods like crackers, toast, and plain rice often help. Stay hydrated — sip water or ginger tea throughout the day.
Avoid the obvious risks. No alcohol, limit caffeine to 200mg daily (about one large coffee), and avoid unpasteurised dairy, raw meat, and certain fish high in mercury.
Rest. Seriously. The fatigue is real and your body needs it. Say no to things. Nap. This phase is temporary.
When to Call Your Doctor
Most symptoms at 6 weeks are normal, even when they feel awful. But some symptoms need immediate attention:
Call your GP, midwife, or NHS 111 if you have:
- Heavy bleeding (soaking through a pad in an hour)
- Severe abdominal pain, especially one-sided
- Shoulder tip pain combined with abdominal pain
- Dizziness or fainting
- Fever over 38°C
- Severe vomiting with signs of dehydration (very dark urine, inability to keep fluids down for 24 hours)
These symptoms can indicate ectopic pregnancy, miscarriage, or hyperemesis gravidarum — all of which need medical care.
The Bottom Line
Week 6 is hard. The symptoms are real, the fatigue is intense, and the emotional reality of pregnancy is probably starting to sink in. But it's also a week of incredible development — your baby's heart is beating, limb buds are forming, and the neural tube is closing.
If you're struggling with symptoms, know that this phase is temporary. Most women find the nausea and exhaustion ease significantly by 12–14 weeks. Until then, be gentle with yourself. Rest when you need to. Eat what you can. And remember that every challenging symptom is a sign that your body is doing exactly what it needs to do.
▸Can you see a heartbeat at 6 weeks pregnant?
Sometimes, but not always. A transvaginal ultrasound may detect cardiac activity at 6 weeks, but it's also completely normal not to see a heartbeat yet. If there's no heartbeat at 6 weeks, you'll usually be offered a follow-up scan in 7–10 days. Heart rates at 6 weeks typically range from 90–110 beats per minute.
▸Is it normal to have no symptoms at 6 weeks pregnant?
Yes. While many women feel intense symptoms at 6 weeks, others feel relatively normal. The absence of symptoms doesn't indicate a problem. Every pregnancy is different, and some women sail through the first trimester with minimal nausea or fatigue. Try not to compare your experience to others.
▸How big is my baby at 6 weeks pregnant?
At 6 weeks, your embryo measures about 6mm from crown to rump — roughly the size of a pea or sweet pea. It weighs less than a gram. Despite the tiny size, major organs are beginning to form and the heart tube is already beating.
▸Is cramping normal at 6 weeks pregnant?
Mild cramping can be normal as your uterus expands and the embryo implants more deeply. It typically feels like period cramps but lighter. However, severe cramping — especially with heavy bleeding or one-sided pain — needs medical attention to rule out ectopic pregnancy or miscarriage.
▸What should I be eating at 6 weeks pregnant?
Eat what you can tolerate. If morning sickness is severe, focus on getting calories in however you can — crackers, toast, plain rice, bananas. Small, frequent meals often help more than large ones. Stay hydrated. Don't worry about perfect nutrition right now — your baby is getting what they need from your reserves. If you're managing to eat reasonably well, prioritise folate-rich foods (leafy greens, lentils), protein, and healthy fats.
References
- NHS (2024). 6 weeks pregnant guide. NHS Best Start in Life. nhs.uk
- Tommy's (2024). 6 weeks pregnant: baby's development, morning sickness and your emotions. tommys.org
- Doubilet, P.M. & Benson, C.B. (1995). Embryonic heart rate in the early first trimester: what rate is normal? Journal of Ultrasound in Medicine, 14(6), 431–434. PubMed: 7658510
- American Pregnancy Association (2023). Early Fetal Development. americanpregnancy.org
- BabyCenter (2017). 6 weeks pregnant: Ultrasound, symptoms, belly, and more. babycenter.com
- Healthline (2022). Your 6-Week Ultrasound: What You Can Expect to See. healthline.com
⚕️ Medical Disclaimer
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, midwife, or other qualified health professional with any questions about your pregnancy. If you experience severe pain, heavy bleeding, or other concerning symptoms, seek medical attention immediately.
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