Pregnancy Week 6: Morning Sickness, Fatigue and Your Baby's Face Taking Shape

8 min read

Quick answer: At 6 weeks your baby is about 5 to 6mm long, roughly the size of a lentil, with the heart beating, dark spots forming where the eyes will be and limb buds appearing. Morning sickness and heavy fatigue often peak now. Eat little and often, try ginger, and contact your GP or midwife if you cannot keep fluids down.

What parents need to know

Week 6 is a big one in early pregnancy. For many mums-to-be, this is the week when morning sickness makes itself known, though despite the name, nausea can strike at any time of day or night. Your baby is growing fast, and while you might not look pregnant yet, an enormous amount is happening beneath the surface.

Baby's size	About 5 to 6mm, roughly the size of a lentil
Booking appointment	Typically between weeks 8 and 10
Daily supplements	Folic acid 400mcg and vitamin D 10mcg
Dating scan	Official size confirmed at 12-week dating scan

How big is your baby at 6 weeks?

Your baby is now roughly the size of a lentil, about 5 to 6mm long. That said, ultrasound measurements at this stage can vary, and your baby's official size will be confirmed at your 12-week dating scan.

What's happening with your baby?

This week, your baby's face is beginning to take shape in the most primitive of ways. The areas that will become eyes are forming as dark spots, and tiny pits that will eventually become ears and nostrils are appearing. Most remarkably, your baby's heart is now beating and pumping blood, even at this tiny size. If you have an early scan around this time (usually offered only if you've experienced bleeding or pain, or following fertility treatment), you may be able to see this flicker of movement on the screen.

Your baby's limb buds — the very early beginnings of arms and legs — are also starting to develop. The brain and nervous system continue to grow rapidly, and the neural tube, which will become the spinal cord, is closing. All of this incredible work is happening in something smaller than a blueberry.

A heartwarming close-up of a baby's face showcasing innocent eyes with a soft, gentle expression.

What's happening in your body?

Week 6 is often when pregnancy symptoms are felt most keenly. Rising levels of hCG (the pregnancy hormone) are thought to be a key driver of nausea, though exactly why morning sickness occurs is still not fully understood. What we do know is that it affects the majority of pregnant women to varying degrees, and — reassuringly — experiencing nausea is often a sign that the pregnancy is progressing well.

Common symptoms at week 6

Nausea and vomiting are the most talked-about symptoms at this stage, but you may also notice heightened fatigue — the kind of tiredness that feels unlike ordinary tiredness and may be hard to push through. Your breasts are likely to be tender and may have grown slightly. You might find yourself suddenly repulsed by foods or smells you used to love; food aversions are extremely common in the first trimester. Some women experience excess saliva (known as ptyalism) or a metallic taste in their mouth. Constipation is also common, caused by the hormone progesterone which relaxes smooth muscle tissue throughout the body, including the digestive system.

Managing morning sickness

There is no single remedy that works for everyone, but these strategies, supported by the NHS and Tommy's, can help reduce the impact of nausea:

Eat little and often: an empty stomach can make nausea worse. Keep plain crackers, breadsticks, or rice cakes nearby, including by your bed for when you wake up. There's some evidence that ginger may help with nausea, for example in ginger biscuits or ginger tea. Check with your pharmacist before taking ginger supplements, such as capsules, in pregnancy. Cold foods, such as yoghurt or sandwiches, are often easier to tolerate than hot meals. Stay well hydrated by sipping water, diluted juice, or ice lollies throughout the day. Avoid fatty, spicy, or strongly scented foods if they trigger your symptoms.

If your nausea and vomiting are severe and you're unable to keep fluids down, you may have a condition called hyperemesis gravidarum (HG). This is more than ordinary morning sickness and requires medical treatment, so please contact your GP or midwife if you're struggling to stay hydrated or are losing weight.

Looking after your mental wellbeing

Feeling tired, nauseous, and unable to share your news with many people yet can make the first trimester feel isolating. Many women describe feeling as though they're carrying a secret while also not feeling well enough to carry on as normal. This can be emotionally draining.

It's entirely OK to ask for support from a partner, close friend, or family member; you don't have to tell everyone you're pregnant to have some extra help. Many women find the NCT or Tommy's online communities a source of reassurance during the early weeks. And if you're struggling emotionally, your GP can offer referrals and support.

Your booking appointment

If you haven't already contacted your GP to arrange a midwife referral, do so this week. Your booking appointment will typically take place between weeks 8 and 10, and involves a detailed health assessment, blood tests, and information about your antenatal care. Getting this booked promptly means nothing is delayed.

When to get help

Some symptoms in pregnancy can be a sign of something serious and need checking quickly. This is who to contact, and how soon.

Call 999 if:

you're bleeding from your vagina and the bleeding is heavy (soaking a period pad soon after putting it on), or you also have severe pain in your tummy, pain in your shoulder, or feel sick, faint, dizzy or lose consciousness
you have a sharp, sudden and intense pain in your tummy together with feeling very dizzy or fainting, feeling sick or looking very pale, as this could mean an ectopic pregnancy has ruptured (you can also go straight to A&E)
you have severe difficulty breathing (you're gasping, choking or not able to get words out) or your chest feels tight or heavy
you have pain and swelling in one leg and you also feel short of breath or have chest pain. A blood clot in the leg can travel to your lungs, which can be life-threatening
you have possible signs of sepsis, such as breathing very fast, being confused or having slurred speech, blue, pale or blotchy skin, a rash that does not fade when you press it, or a very high or very low temperature. Being pregnant makes sepsis more likely
you do not feel you can keep yourself safe (a mental health emergency is as serious as a physical one)

Always call 999 if you think it's a life-threatening emergency, no matter what stage of pregnancy you are.

Contact your GP or early pregnancy unit right away if:

you have light bleeding or spotting, even if you have no pain or only mild tummy pain
you have vaginal discharge that's unusual for you, or fluid leaking from your vagina
you have tummy pain low down on one side, or pain in the tip of your shoulder (where your shoulder ends and your arm begins). Symptoms of an ectopic pregnancy usually start between 4 and 12 weeks, so get advice right away, even if you have not had a positive pregnancy test yet
you have stomach pain that is severe or does not go away after you've rested for 30 to 60 minutes, or stomach pain with regular cramping or tightenings, lower back pain, or pain when you pee
your breathlessness comes on suddenly, you're out of breath when you're lying down, or you're breathless and also have chest pain or feel dizzy
you have pain or swelling in one leg, usually in the calf or thigh. This could be a blood clot (deep vein thrombosis, or DVT), which is more likely when you're pregnant
you have a high temperature (38C or above), or you feel hotter than usual or shivery. A high temperature can be a sign of an infection, so it's important to get it checked

If you cannot reach them, or you're not sure what to do, call NHS 111.

Call your midwife, GP or NHS 111 if you're being sick and you:

have very dark pee, or have not had a pee in more than 8 hours
cannot keep food or fluids down for 24 hours
feel very weak, dizzy or faint when you stand up
have tummy pain
have a high temperature
vomit blood
have lost weight

If you're being sick often and cannot keep food down, tell your midwife or doctor, or contact the hospital, as soon as possible. You may be at risk of dehydration and need treatment.

Speak to your GP or midwife if:

you're worried about your mental health, or stress, anxiety or low mood are affecting your day-to-day life. If you need urgent help for your mental health, call 111 and select the mental health option, or ask for an urgent GP appointment

Your week 6 checklist

This week:

This week

Contact your GP if you haven't already.
Manage morning sickness with small, frequent meals and ginger.
Rest as much as you need: fatigue is real and valid.
Continue taking folic acid (400mcg) and vitamin D (10mcg) daily.
Note any severe symptoms to discuss with your midwife or GP.
Be gentle with yourself. You're growing a human.

Sources: NHS, Tommy's, NCT. General information, not medical advice.

Sources & further reading

General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.