6 weeks pregnant: symptoms and baby development
Tiny buds where arms and legs will grow.
First trimesterMonth 25 min read
By Solesia, from public clinical guidanceUpdated
You wake up and the smell of coffee is wrong. Or the thought of dinner turns your stomach at eleven in the morning, or you are fine all day and seasick by evening. However it shows up, and some people are spared it altogether, the queasiness of early pregnancy tends to begin about now, and it comes from hormones doing exactly what they are meant to do. Your baby, meanwhile, has doubled in size in a week and is starting to look less like a tube and more like someone, with a head, a curled body and the first small buds where arms and legs will be.
How big is your baby at 6 weeks
About the size of a sweet pea
0.25 in long·under 0.1 oz
Baby development at 6 weeks
At 6 weeks your baby measures about 0.25 inches, the size of a sweet pea, and they are curled into the shape of a C. Small paddle-shaped buds have appeared on each side of the body, arms first and legs a few days behind. On the head, dark spots mark where the eyes are forming and shallow dents show where the ears will be.
The heart, which started beating last week, is now quick and steady, around 100 to 120 beats a minute and rising. On a vaginal ultrasound it shows as a flicker of movement, and that flicker is the reason an early scan is sometimes done now. The tube along the back has closed, and the brain at the top of it is dividing into the sections that will run their body.
Everything sits under a layer of skin so thin it is transparent, with the organs visible through it. The liver has started, and for now it is busy making blood cells, a job that bone marrow will take over later. The placenta is still growing into your uterine wall and is weeks from carrying the full load.
Your body at 6 weeks
Nausea now is expected, whether it stays as queasiness or tips into vomiting, and despite the name it can hit at any point in the day. Rising hCG and estrogen, a slower stomach and a sharper sense of smell all feed into it. An empty stomach makes it worse, so small amounts of food often, plain crackers before you get out of bed, and cold food instead of hot all take the edge off. It usually eases by 14 weeks.
Headaches are common this week, from the same hormones and from the extra blood your body is making. Water, regular meals and rest help; acetaminophen is fine if you need it, and ibuprofen and aspirin are best left alone unless your provider says otherwise.
Your sense of smell may be so sharp that the coffee pot, the fridge or a coworker’s lunch turns your stomach. That is expected and it passes. Fresh air, lemon and mint are the smells people find easiest.
Common pregnancy symptoms at 6 weeks
- Nausea, at any hour. hCG and estrogen, and a slower stomach. Eat before you are hungry; small and often, cold and plain.
- Headaches. Hormones and more blood. Water, food on time, and acetaminophen if needed.
- A sharp sense of smell. Estrogen at work. Open windows, cold food, and someone else cooks.
- Sore breasts. Glands and blood flow growing. A soft bra, worn to bed if it helps.
- Mood swings. Hormones on top of everything being new. Sleep, and lower the bar for the week.
- Bloating. Progesterone relaxing the gut. Small meals, water, and a walk after eating.
- Light spotting. Common in early weeks and usually brown or pink. Bleeding like a period is the one to call about.
When to call your provider at 6 weeks
Feeling sick is expected. Not being able to keep fluids down for a day is the point to call your provider.
Two things are worth a same-day call at any point in pregnancy: bleeding that is more than spotting, and pain that is severe or does not ease. From the second trimester, add fluid leaking and any change in your baby’s usual pattern of movement. You do not need to be sure something is wrong to call; that is what the number is for.
What to do at 6 weeks
- Which medicines are fine. Acetaminophen for pain, plain antacids for heartburn, and many allergy tablets are considered safe. Ibuprofen, naproxen and aspirin are not, unless prescribed. If in doubt, one call to the office settles it.
- An early ultrasound, if one is offered. Some providers scan around 6 to 8 weeks to confirm the pregnancy is in the uterus and to date it. It is done vaginally this early, takes a few minutes, and can show the heartbeat as a flicker.
- Help with nausea. Vitamin B6 and doxylamine, a sleep-aid antihistamine, are the first things providers suggest, and both are sold without a prescription. Ginger helps some people. Ask before adding anything else.
- Quitting smoking. If you smoke and have not managed to stop, this is the week to get help rather than willpower. Your provider can suggest nicotine replacement, and 1-800-QUIT-NOW is free.
Common questions at 6 weeks
What does a 6 week ultrasound show?
A small round sac in the uterus, the yolk sac inside it, and often a tiny embryo with a flickering heartbeat. Measurements give a due date accurate to a few days. If the embryo is too small to see, that usually means the dates are a little off, and the scan is repeated a week or two later.
Is it normal to have no morning sickness at 6 weeks?
Yes. About seven in ten pregnant people get nausea at some point, which leaves plenty who do not, and how sick you feel says nothing about how the pregnancy is doing. For some it starts at 8 or 9 weeks; for others it never comes. Enjoy it.
What can I take for nausea at 6 weeks pregnant?
Start with food: something plain every two hours, crackers before you get up, and cold meals. Over the counter, vitamin B6 up to 25 mg three times a day, with doxylamine at night, is the combination providers recommend first. If you cannot keep fluids down for a day, call: there are prescription options that work.
What painkillers can I take while pregnant?
Acetaminophen is the one to reach for, at the normal dose, for headaches, backache or fever. Ibuprofen, naproxen and aspirin are avoided in pregnancy unless your provider has prescribed a low-dose aspirin for a specific reason. For a headache, water and food often do as much as a tablet.
Written from public clinical guidance, including NHS: Week 6, ACOG: How your baby grows, ACOG: Nausea and vomiting, NHS: Morning sickness, NHS: Headaches and ACOG: Bleeding. This page is general information, not medical advice, and does not replace your provider.