8 weeks pregnant: your baby becomes a fetus and your care begins
The end of month two: your baby's organs are all developing, your placenta is anchoring itself, and your first big appointment is near.
Updated October 13, 2026 · sources checked October 13, 2026
In short
At 8 weeks you reach the end of month two. The NHS says your baby is around 16 mm and will be twice the size by next week; around now the embryo becomes a fetus. Your booking appointment usually falls between 8 and 12 weeks. The one thing to do this week: prepare your questions and your health history for that first appointment.
Where you are at 8 weeks
Eight weeks marks the end of month two in Cleveland Clinic's grouping, still well inside the first trimester. Cleveland Clinic says that by the end of this month the fetus is about half an inch to one inch long. If you are unsure of your dates, the pregnancy week calculator and your dating scan will set them.
Your baby this week
The NHS gives a length of around 16 mm and compares your baby to a raspberry, adding that by next week your baby will be about twice that size.
- The head has started to uncurl a little. Arms are getting longer and are bigger than the legs, because the upper body grows faster (NHS).
- Knees, ankles and toes have not developed yet.
- Cleveland Clinic says all major organs and body systems are developing, hands and feet are web-like, and the umbilical cord is fully formed, carrying oxygen and blood.
- The placenta is sprouting little branches to attach itself to the wall of the womb (NHS).
Embryo or fetus? The NHS says your baby becomes a fetus around now; Cleveland Clinic says after week 8; ACOG counts it from 9 weeks after fertilisation. Same milestone, slightly different wording.
Your body: mood, bloating and peeing at night
You may feel tired and sick, bloated, and your breasts may be slightly swollen. The expanding womb presses on your bladder, so you pee more often. If it disturbs your sleep, drink plenty during the day and a bit less in the evening (NHS).
Feeling anxious or low? The NHS calls it the pregnancy blues and suggests rest, six small healthy meals a day and perhaps mindfulness. Above all, share your worries: your midwife or doctor is the right place to start.
Is this normal? When to call
Period-like cramps and a little spotting can happen, but always mention bleeding. Call your early pregnancy unit, maternity unit or NHS 111 (UK), or your OB-GYN or midwife (US), if you have bleeding, one-sided tummy pain, vomiting so severe you cannot keep fluids down, or a temperature of 38C (100.4F) or above. Call 999 or 911 for bleeding with severe pain, shoulder-tip pain, or if you feel faint.
Sometimes a pregnancy ends with no symptoms and is only found at a scan, which the NHS calls a missed miscarriage. ACOG says early loss happens in about 10 of 100 known pregnancies and is not your fault. Kind, free support exists: Miscarriage UK, 0303 003 6464, and Share Pregnancy and Infant Loss Support in the US.
Appointments: your booking or first prenatal visit
UK. The booking appointment usually happens between 8 and 12 weeks and lasts around an hour (NHS). Your midwife will ask about your last period, past pregnancies, health conditions, mental health, work and home situation, check your blood pressure and urine, offer a blood test for your blood group, and give you your maternity notes. You will be offered screening tests, including for infections and Down's syndrome. NHS care includes at least 10 appointments and 2 scans for a first baby.
US. ACOG lists routine early tests: blood type and Rh factor, a urine culture, and screening for infections such as syphilis, and chlamydia and gonorrhoea for some. This is also the time to discuss genetic screening options available from 10 weeks.
Your week 8 checklist
For your partner
Come to the first appointment if you can, and help her remember the questions she wanted to ask.
Previous and next week
Week 7: brain growth and extra blood · Week 9: the hormone peak · The first trimester · All weeks · Due date calculator
Questions parents ask
I am 8 weeks pregnant and it feels like my period is coming. Is that normal?
Mild cramping a bit like period pain is listed by the NHS among normal early pregnancy symptoms, often as the womb grows. If cramps are strong, one-sided or come with bleeding, call your early pregnancy unit, GP, NHS 111 or your OB-GYN the same day.
When does an embryo become a fetus?
Sources word it slightly differently. The NHS says the embryo becomes a fetus around week 8; Cleveland Clinic says after the 8th week; ACOG counts from 9 weeks after fertilisation. They describe the same transition, around the end of month two.
Can stress cause a miscarriage at 8 weeks?
ACOG states that work, exercise, stress, arguments and sex do not cause miscarriage, and that early loss is usually a random event. If you are feeling very stressed, that matters for you, so talk to your midwife or doctor.
Sources
- NHS — Week-by-week guide: week 8 checked October 13, 2026
- Cleveland Clinic — Fetal development: week-by-week stages of pregnancy checked October 13, 2026
- NHS — Antenatal (pregnancy) care and appointments checked October 13, 2026
- ACOG — How Your Fetus Grows During Pregnancy checked October 13, 2026
- ACOG — Routine Tests During Pregnancy checked October 13, 2026
- ACOG — Early Pregnancy Loss checked October 13, 2026
Mamavela explains; it does not replace your midwife, doctor or pediatrician, who know your situation. If something worries you, call them. In an emergency, call 911 (US), 999 (UK) or 112.