7 weeks pregnant: a fast-growing brain and more blood for two
Your blood volume is rising, your baby's brain is racing ahead, and you may be wondering when to tell anyone. All of it at your own pace.
Updated October 13, 2026 · sources checked October 13, 2026
In short
At 7 weeks you are in month two of the first trimester. The NHS says the embryo is around 10 mm long, with a brain growing faster than the rest of the body. Your blood volume is rising, which can make you thirsty. The one thing to do this week: drink regularly, rest, and decide calmly who you want to tell, and when.
Where you are at 7 weeks
You are in month two (weeks 5 to 8, as Cleveland Clinic groups them) of the first trimester. The NHS notes that the womb is now about the size of a lemon. If this is your first pregnancy you may not look pregnant until around 12 weeks; if you have had a baby before, it can show sooner. Your exact week and day are in the pregnancy week calculator.
Your baby this week
The NHS gives a length of around 10 mm from head to bottom and compares the embryo to a grape.
- The brain grows faster than the rest of the body, giving a large forehead. The NHS says around 100 new brain cells are being made every minute.
- There are small dimples where the nose and ears will be, and eyelids are beginning to grow over the eyes.
- Limb buds are forming cartilage, the arm buds are getting longer and their flattened ends will become hands.
- Cleveland Clinic adds that bone is beginning to replace soft cartilage and the head is large in proportion to the body.
Your body: extra blood, thirst and fatigue
There is more blood in your body than seven weeks ago, and the NHS says your blood volume will rise by up to 50% over the pregnancy to feed the womb. That is part of why you may feel tired and thirsty.
- Drink regularly. The NHS suggests about 8 medium glasses of fluid a day, such as water, fruit tea or milk.
- Eat little and often if nausea is still around (see week 6 tips).
- Do not ignore odd symptoms, such as feeling itchy all over. The NHS says most aches are a normal part of pregnancy, but check anything unusual with your midwife or doctor.
When to tell people
Who you tell, and when, is entirely your choice. Some people tell close family straight away for support; others wait until after the first scan. If you have had a loss before or conceived after a long journey, you may want a small circle for now, and that is fine.
At work, the legal deadline in the UK is later than many people think: you must tell your employer at least 15 weeks before your due date (GOV.UK). In the US, the Pregnant Workers Fairness Act gives you the right to reasonable adjustments, such as more breaks or time off for appointments, with employers of 15 or more employees (EEOC); to ask for them, your employer needs to know.
Is this normal? When to call
Call your early pregnancy unit, maternity unit, GP or NHS 111 (UK), or your OB-GYN or midwife (US), for any vaginal bleeding, unusual discharge or fluid leaking, or pain on one side of your tummy. Call 999 (UK) or 911 (US) if you are bleeding and have severe tummy pain, shoulder pain, or feel sick, faint or dizzy (NHS).
The NHS week-7 guide also reminds you that a miscarriage is the loss of a pregnancy in the first weeks, and offers clear information on symptoms. ACOG says it happens in about 10 of 100 known pregnancies and is usually not caused by anything the pregnant person did. Support: Miscarriage UK, 0303 003 6464; Share Pregnancy and Infant Loss Support in the US.
Appointments coming up
- UK: your booking appointment with a midwife is usually between 8 and 12 weeks (NHS). If it is not booked yet, chase it this week.
- US: if you have not had your first prenatal visit, call to book one. Bring a list of medicines and your period dates.
- Both: if you need a dating date and do not know your last period, ask about an early dating ultrasound (ACOG).
Your week 7 checklist
For your partner
Let her decide when and how to share the news, and keep the secret well if that is the plan.
Previous and next week
Week 6: limb buds and nausea · Week 8: from embryo to fetus · The first trimester · All weeks · Due date calculator
Questions parents ask
What are the signs of a miscarriage at 7 weeks?
The NHS says the main symptom is usually vaginal bleeding, which can range from spotting to heavy bleeding, sometimes with cramping in the lower tummy, lumps of tissue or a sudden fluid loss. Bleeding has other causes too and is not always serious, but always call your maternity unit, early pregnancy unit, NHS 111 or your OB-GYN. Call 999 or 911 if you have heavy bleeding with severe pain, shoulder pain or feel faint.
Do I have to tell my employer I am pregnant at 7 weeks?
No. In the UK, GOV.UK says you must tell your employer at least 15 weeks before your due date. Many people wait until after the first scan. Telling earlier can help if you need adjustments or time off for appointments.
Why am I so thirsty at 7 weeks pregnant?
The NHS explains that the volume of blood in your body rises during pregnancy, by up to 50%, to supply the womb. This can make you thirstier than usual, so keep a drink nearby.
Sources
- NHS — Week-by-week guide: week 7 checked October 13, 2026
- Cleveland Clinic — Fetal development: week-by-week stages of pregnancy checked October 13, 2026
- GOV.UK — Maternity pay and leave: how to claim checked October 13, 2026
- NHS — Miscarriage 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.