Your baby is an embryo about 3 to 6 mm long this week, reaching around 6 mm by the week's end, roughly the size of a lentil or a small baked bean, the size the NHS gives for this week [1]. Big structural work is underway this week. MedlinePlus writes that "Your baby's brain, spinal cord, and heart begin to develop" and that the gastrointestinal tract starts to form [2].
The heart is one of the earliest organs to work. By around this point it beats in a regular rhythm, and it can sometimes be seen on a transvaginal ultrasound [3]. The rate is naturally lower at 6 weeks than it will be later in the first trimester, and it climbs over the following weeks as the heart matures. If an early scan measures the rate, your provider will interpret the number together with your dates, since even a few days' difference in timing changes what is expected.
Here is the honest picture of a 6 weeks pregnant ultrasound. In early pregnancy the scan is usually done transvaginally, with a slim probe, because that gives a clearer image this small [9]. A scan around now may show the gestational sac, and sometimes a fetal pole and an early flicker of cardiac activity. It can also be too early to see a heartbeat, especially if dates are off by even a few days. A single early scan without a visible heartbeat is often just a timing question, not bad news, and doctors typically repeat the scan in a week or two before drawing any conclusion [7].
Whether you get a scan this early depends on your provider. In the United States, many practices do a first ultrasound between 8 and 14 weeks, often as part of early prenatal care, and the exact timing varies by practice [15]. In some health systems, such as the UK's NHS, the routine dating scan that confirms the heartbeat, checks how many weeks along you are, and sets your due date is offered around 10 to 14 weeks [8]. If you do have an early scan, treat what it shows as a first snapshot rather than a final verdict.
Nausea is the symptom people notice most around now. The NHS writes that "Morning sickness can occur at any time of day, although it's usually worse when you first wake up", and ACOG puts the usual start before 9 weeks [5]. For many, nausea and vomiting of pregnancy starts before 9 weeks, builds toward a peak in the following weeks, and eases by about 14 weeks, though for some it lasts longer [4]. Taking a prenatal vitamin before pregnancy is linked to a lower risk of severe nausea and vomiting [4].
Food aversions and a sharper sense of smell are common this week too. The NHS writes that in early pregnancy "you may find you no longer like some foods or drinks you used to enjoy", and lists a strange taste some describe as metallic, along with new cravings [5]. That is a normal hormonal change, not a sign anything is wrong with your eating.
Fatigue often lands hard around 6 weeks. The NHS writes that it is common to feel tired "or even exhausted" in the first 12 weeks or so, and that hormonal changes at this time "can make you feel tired, sick, emotional and upset" [5]. The NHS writes that breasts "may become larger and feel tender" and that "You may feel the need to pee more often than usual, including during the night" [5].
Spotting deserves a calm, clear word. Light bleeding or spotting can happen in early pregnancy, and the cervix also bleeds more easily now because more blood vessels are forming there [6]. A small amount of bleeding early on is common and does not necessarily mean you will have a miscarriage [6]. It is still worth telling your doctor, and the next section covers what makes bleeding more urgent.
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Browse the week by week Learn libraryBook your first prenatal visit. Call your provider and schedule your first checkup as soon as you know you are pregnant [12]. That first appointment is usually the longest, and it sets up your care for the months ahead.
Take folic acid every day. In the United States the CDC recommends 400 micrograms of folic acid daily for anyone who could become pregnant, because it helps prevent serious birth defects of the brain and spine called neural tube defects [11]. The neural tube is closing this very week, which is exactly why the timing matters. Many national guides give the same 400 microgram figure and suggest continuing at least through the twelfth week [13], and WHO recommends daily folic acid starting as early as possible after conception [14]. If you take a prenatal vitamin, check that it includes folic acid [12].
Write down the first day of your last menstrual period. Your provider uses that date to estimate your due date, so having it ready makes your first visit smoother [12].
Work with the nausea, gently. Small diet and lifestyle changes can help you feel better [4]. Eating small amounts often and keeping fluids nearby are reasonable places to start, and if you were taking a prenatal vitamin before pregnancy, that habit may lower the odds of severe symptoms [4].
Set realistic expectations for scans. You may not be offered an ultrasound this early, and that is standard for many practices. In the US, a first ultrasound often happens between 8 and 14 weeks, depending on your provider [15], and in some health systems the routine dating scan comes around 10 to 14 weeks [8].
It is best to contact your ob-gyn about any bleeding at any point in pregnancy [6]. Light spotting is often nothing serious, and calling does not mean you are overreacting.
Call right away if your bleeding is heavy, or if it comes with pain like menstrual cramps [6]. Reach out promptly if you cannot keep food or fluids down and are losing weight, since severe, ongoing vomiting needs medical attention [4].
Severe pain on one side of your lower belly, pain in the tip of your shoulder, or feeling faint or dizzy, with or without bleeding, can be signs of an ectopic pregnancy, when the pregnancy grows outside the uterus [10]. This is an emergency. Call 911 or go to the emergency room right away.
Trust your read on your own body. If something feels sharply wrong, do not wait to be sure. When in doubt, a phone call to your care team is always a fair choice, and for anything that feels like an emergency, call 911.
This is a good week to be the steady one. Nausea, exhaustion, and a nose that suddenly hates coffee are real, and they are not something to fix, just to make room for. Offer plain crackers, a full water glass, and a quiet house when she needs to lie down [5].
You can also carry a couple of practical things. Help book that first prenatal appointment, and keep a note of the first day of her last period so it is ready for the visit [12]. Small, reliable help counts more than big gestures right now.
Six weeks in, feelings often arrive in a jumble. Excitement, worry, numbness, and tenderness can all show up in the same afternoon, and none of them means you are doing this wrong. Early pregnancy sits in a quiet, waiting space, before most people around you even know, and that can feel lonely even when the news is wanted.
It is normal to scan your body for symptoms and to notice when they come and go, since nausea and tiredness naturally rise and fall day to day [4]. Try to hold your worry loosely. A small amount of spotting is common and does not decide the outcome [6], and the early weeks are simply uncertain for everyone, not because of anything you did. If low mood or anxiety feels heavy or constant, tell your provider at your first visit [12]. You are allowed to ask for support this early.
At 6 weeks the embryo is about 3 to 6 mm long, reaching around 6 mm by the end of the week, and the NHS puts this week at the size of a baked bean [1]. Its brain, spinal cord, and heart are all beginning to form this week [2].
Sometimes. A transvaginal ultrasound around 6 weeks may show early cardiac activity, but it can also be too soon to see a heartbeat, often just because of small differences in dating [3][9]. If none is seen this early, doctors usually repeat the scan in a week or two before drawing any conclusion [7].
The heart beats in a regular rhythm by around this point in development [3]. Its rate is naturally lower at 6 weeks than it will be later in the first trimester and rises over the following weeks, so there is no single number to hold on to this early. If an early scan measures the rate, your provider will interpret the number together with your dates, since even a few days' difference in timing changes what is expected.
Light spotting can happen in early pregnancy, partly because the cervix bleeds more easily as new blood vessels form [6]. A small amount of bleeding early on is common and does not necessarily mean miscarriage, but you should still tell your doctor, and call right away if bleeding is heavy or comes with cramping pain [6]. If bleeding or pain comes with severe one-sided belly pain, shoulder-tip pain, or faintness, call 911 or go to the emergency room, since these can be signs of an ectopic pregnancy [10].
ACOG writes that nausea and vomiting of pregnancy usually starts before 9 weeks and that for most women it goes away by 14 weeks. The NHS writes it can occur at any time of day [4][5]. For many it builds toward a peak in the weeks just after 6 weeks, and taking a prenatal vitamin before pregnancy is linked to a lower risk of severe symptoms [4].
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