Being 8 weeks pregnant covers days 56–62 after the first day of your last period (8+0 to 8+6 weeks); it is the week you move from the 2nd to the 3rd month of pregnancy. According to the NHS, your baby is about 16 mm long. The crown-rump length measured around now is the most accurate way to set your due date.
About 1 month and 26 days have passed since the first day of your last period; 8 weeks pregnant is the end of the 2nd month and the start of the 3rd month of pregnancy.
According to the NHS, your baby is about 16 mm long, about the size of a raspberry. The tiny head has started to uncurl a little. Because the upper body grows faster than the lower body, the arms are longer than the legs; the legs are getting longer too, but the knees, ankles, thighs and toes have not developed yet.
ACOG lists the following for the first 8 weeks of pregnancy: the brain and spine begin to form, heart tissue develops, the muscles of the eyes, nose and mouth form, webbed fingers and toes poke out from the developing hands and feet, the lungs start to form the tubes that will carry air, and the inner ear begins to develop (ACOG, 2026).
The placenta is getting ready too: according to the NHS, it is sprouting little branches that will attach it to the wall of the womb, preparing to supply nutrients and oxygen and remove waste.
When does an embryo become a fetus? Sources give different answers: the NHS says the embryo becomes a “foetus” around now; ACOG defines the first 8 weeks after fertilisation as the embryo stage and the fetal stage as starting from 9 weeks after fertilisation. UpToDate states that the embryonic period ends at the end of the 10th week of pregnancy (the 8th week after conception), and notes that ultrasound reports prefer “embryo” up to 10+6 weeks and “fetus” after 11+0 weeks.
You may feel bloated and notice your breasts are slightly bigger, but it will probably be a few more weeks before your bump shows (NHS). Tiredness and nausea may continue. As your growing womb presses on your bladder you may need to pee more often; if this disturbs your sleep, the NHS suggests drinking plenty during the day and less in the evening.
There may be times when you feel anxious and stressed. The NHS suggests resting as much as you can, eating 6 small healthy meals a day and sharing your worries with your midwife or doctor.
Weight gain: weight gain in the first trimester is small. The US Institute of Medicine (IOM) recommendations assume a gain of 0.5–2 kg in the first trimester (IOM, 2009). The Turkish Ministry of Health guideline advises a gain of no more than 2 kg a month for underweight and normal-weight women, and no more than 1 kg a month for women with overweight or obesity. You can use our pregnancy weight tool for your own chart.
First appointment and first scan: organisations give different timings:
Flu vaccine: the Turkish Ministry of Health guideline recommends the flu vaccine for pregnant women during the flu season (September to April). The NHS also notes that the flu vaccine can be given at any stage of pregnancy in autumn or winter. See our vaccines in pregnancy guide for details.
The crown-rump length (CRL) measured at this stage is the most accurate way to set your due date: up to 8+6 weeks the margin of error is ±5 days, rising to ±7 days at 9+0 to 13+6 weeks. The due date set by the first scan is not changed by later scans (UpToDate, 2026).
| Symptom | Usually | Seek care if |
|---|---|---|
| Needing to pee often | It is common because the growing womb presses on the bladder (NHS). | Seek care if you also have a fever; the Turkish Ministry of Health guideline lists fever among the danger signs in pregnancy. |
| Bloating and wind | The NHS lists feeling bloated among the common symptoms this week. | Do not wait if you have severe abdominal pain, which is one of the danger signs in the Turkish Ministry of Health guideline. One-sided pain and bleeding need checking for ectopic pregnancy, whose symptoms typically appear 6–8 weeks after the last period (UpToDate). |
| Spotting or bleeding | Bleeding is common in the first trimester and most women who bleed do not miscarry (UpToDate), but because it also occurs with miscarriage and ectopic pregnancy it is not treated as normal. | The NHS advises seeing a doctor for any bleeding; the cause is usually clarified with an ultrasound scan. Mention it if your blood group is Rh negative. |
Most of these are danger signs or emergency referral criteria in the Turkish Ministry of Health guideline; the ectopic pregnancy signs and the 12-hour threshold for severe vomiting are based on UpToDate (UpToDate, 2026). The NHS also advises seeing a doctor for any bleeding in pregnancy. Contact your doctor or go to the nearest emergency department without waiting; for sudden severe abdominal pain, fainting or shoulder-tip pain, go straight to the emergency department.
Being 8 weeks pregnant is about 1 month and 26 days since the first day of your last period; it is the week you move from the 2nd to the 3rd month of pregnancy.
According to the NHS, the baby is about 16 mm long this week, about the size of a raspberry.
No. According to ACOG, the genitals begin to form during weeks 9 to 12 of pregnancy. According to UpToDate, the sex is usually identified on ultrasound at 17 to 20 weeks, while a cell-free DNA blood test can also report the sex at 10 to 13 weeks. That test is done mainly to screen for chromosomal conditions.
Bleeding is common in early pregnancy, and most women who bleed do not miscarry (UpToDate, 2026). The NHS still advises seeing a doctor for any bleeding, because an ultrasound scan is usually needed to find the cause. If your blood group is Rh negative and you miscarry before 12 weeks, organisations differ on the anti-D injection: ACOG (2024) does not consider Rh testing and anti-D necessary for a miscarriage before 12 weeks, but allows them on an individual basis; NICE (2026) does not offer anti-D for miscarriage, threatened miscarriage or ectopic pregnancy up to 11+6 weeks; SMFM (2024) recommends Rh testing and anti-D; and UpToDate suggests giving anti-D after a pregnancy loss at any stage of pregnancy, because the evidence is insufficient. The decision is made with your doctor; always tell them your blood group.
Weight gain in the first trimester is small: the IOM recommendations assume a gain of 0.5–2 kg during this time. Most weight is gained in the second and third trimesters. The Turkish Ministry of Health guideline advises no more than 2 kg a month for underweight and normal-weight women, and no more than 1 kg for women with overweight or obesity.
Last updated: . All sources have been confirmed with their latest versions. This content is for educational purposes and is not a substitute for a doctor's examination.