At 6 weeks pregnant, your baby is about 6 mm long, roughly the size of a lentil, and its heart is beating. A vaginal or abdominal scan may show a tiny flicker on the screen. It is also the week when nausea often arrives in earnest.

If you are queasy, tired and wondering how you will get through the next few weeks, this guide gives you a practical plan. It also explains where normal sickness ends and where you need medical help.

Your baby this week

The heart is now a tube that beats regularly, and a scan may detect this activity. The neural tube is closing, and the brain is dividing into distinct regions. Small buds that will become arms and legs are appearing, and dark spots mark where the eyes will form. There are also folds where the ears and nostrils will develop.

The embryo is curled in a C-shape, and the head is large compared with the rest of the body. The placenta is developing, and the yolk sac is providing early nourishment until the placenta takes over.

How it happens. Cells in the developing heart tube contract on their own, in a rhythm set by specialized pacemaker cells. The heartbeat is much faster than yours, often between 100 and 160 beats a minute at this stage. It gets faster over the next few weeks before settling.

Your body this week

If you are not yet nauseous, you may feel it start now. Sickness is thought to be related to rising hCG and estrogen, although the full reason is not known. Your sense of smell is often sharper, and foods you enjoyed a month ago may now be unbearable.

Your breasts may be sore and heavier, and you may have to urinate at night. Your waist may feel thicker, mostly because of bloating rather than growth in the uterus.

Most people do not look pregnant at 6 weeks, and any change in shape is due to bloating. If you have had a positive test but feel no different, that is also normal.

Common symptoms at 6 weeks

  • Nausea, with or without vomiting. It may come in waves or last most of the day.
  • A strong sense of smell. Cooking odours, coffee, perfume and cleaning products can all trigger nausea.
  • Excess saliva. Some people notice a metallic taste or more saliva than usual.
  • Headaches. Hormone shifts and changes in blood pressure or hydration can trigger them.
  • Constipation. Progesterone slows digestion, and iron supplements can make it worse.
  • Sore breasts and darker nipples. Blood flow and hormone changes prepare the breasts for milk production.

A morning sickness playbook

Morning sickness affects most pregnant people to some degree, and the name is misleading because it can happen at any hour. The NHS says it usually clears by weeks 16 to 20. These steps help many people:

  • Eat before you get up. Keep dry crackers or plain toast by the bed and eat a few before you stand.
  • Eat small amounts often. An empty stomach worsens nausea. Try a snack every two hours instead of three large meals.
  • Choose bland, cold foods. Cold foods have less smell. Yogurt, fruit, toast, rice and pasta are common choices.
  • Sip fluids between meals. Drinking a lot at mealtimes can leave you feeling full and queasy. Ice chips, sips of cold water or diluted juice can work when water is hard to face.
  • Try ginger. Ginger tea, chews or biscuits help some people, and it is a widely recommended option. The US NCCIH notes that studies often tested supplements rather than food. Ask your provider before taking ginger supplements.
  • Avoid your triggers. Ask someone else to cook, open a window, or use a fan.
  • Rest. Tiredness makes nausea worse.
  • Talk to your provider about medicine. Several national guidelines suggest vitamin B6, sometimes combined with an antihistamine such as doxylamine, as first-line treatment. What is available depends on where you live, so ask your provider or pharmacist before taking anything. Check the vitamin B6 on every label, because the European upper intake for adults is 12 mg a day and the US limit is 100 mg a day, and a prenatal, a B-complex and a nausea product can add up.

If your prenatal vitamin makes you sick, ask about switching brands or taking it with food at bedtime. Folic acid alone is better than none.

When it is more than morning sickness

A small number of people develop hyperemesis gravidarum, a severe form of pregnancy sickness. It is not the same as everyday nausea, and it needs medical care. It does not mean you are being dramatic, and it is not caused by anything you did.

Contact your provider promptly if:

  • You cannot keep any food or fluid down for 24 hours.
  • You are vomiting many times a day.
  • You pass only small amounts of urine, or it is dark.
  • You feel dizzy, faint or weak when you stand.
  • You are losing weight.

Treatment can include anti-sickness medicines, fluids by drip and sometimes a short hospital stay. Getting help early makes recovery easier. If sickness affects your mood or your ability to work, that also counts. Ask for support.

The 6-week scan and the heartbeat

Some clinics offer an early scan at about 6 weeks, especially if you have had a loss before, have pain or bleeding, or are unsure of your dates. A vaginal scan sees more detail this early than an abdominal one.

If a heartbeat is not seen, it does not always mean a problem. Your dates may be off by a few days, since ovulation may have happened later than you thought. Providers often repeat the scan after a week or so. If you feel worried between scans, tell your provider, and ask what support is available while you wait.

Your week 6 checklist

Call your provider

Call your provider the same day if you cannot keep fluids down for 24 hours, you have signs of dehydration, or you have bleeding, severe pain on one side of your belly, shoulder-tip pain or a fever. This guide is general information and does not replace medical advice.

Frequently asked questions

How can I stop morning sickness at 6 weeks?

There is no single fix. Small frequent meals, cold bland foods, ginger, rest and avoiding triggers help many people. If those are not enough, ask about medicines that are considered suitable in pregnancy where you live.

When does morning sickness peak?

It commonly worsens between weeks 8 and 12 and then improves. The NHS says it usually clears by weeks 16 to 20, but some people have symptoms for longer.

When is nausea a sign of hyperemesis gravidarum?

When you cannot keep fluids down, are passing little urine, feel faint or are losing weight. In that case, contact your provider promptly.

Sources

Sources: NHS: 6 weeks pregnant; NHS: Vomiting and morning sickness; Mayo Clinic: Fetal development, the first trimester; Cleveland Clinic: Fetal development, week-by-week stages of pregnancy; ACOG: Morning sickness; RCOG: Pregnancy sickness patient information; NCCIH: Ginger; EFSA: Vitamin B6 upper intake level, 2023