8 weeks pregnant

How big is your baby at 8 weeks?

About the size of a raspberry — around 16 mm (0.6 in) long, head to bottom. The NHS adds that by next week the baby will be roughly twice this size.

A note on the numbers: in the first trimester babies are measured crown to rump — head to bottom, not head to heel, because the legs are curled. Weight is not reliably estimated this early, so any site quoting grams or ounces before about 14 weeks is guessing.

What's developing this week

The tiny head has started to uncurl. The arms are lengthening and are currently bigger than the legs, because the upper body develops faster than the lower. The legs are growing too, although knees, ankles, thighs and toes have not appeared yet.

Around now the embryo becomes a foetus — a change of terminology rather than of the baby, marking the end of the period when the major structures are first laid down. The placenta is doing significant work this week, sprouting branches that anchor it into the wall of your womb so it can take over delivering nutrients and oxygen.

Your booking appointment

The NHS books the first full antenatal (prenatal) appointment between weeks 8 and 12. It takes about an hour and covers your history, screening tests, and your options for care. If you have not arranged it, this is the week — you can usually self-refer to a maternity service without seeing a doctor first.

What you might feel

Tiredness and nausea are usually still front and centre. You may also need to pee more often as your growing womb presses on your bladder; the NHS suggests drinking plenty during the day and less in the evening if it is wrecking your sleep. Also on the list: a metallic taste, sore breasts, headaches, mood swings, new food likes and dislikes, a heightened sense of smell, discharge, light spotting, cramping, darkened skin patches, thicker hair and bloating.

Mood is worth naming. The NHS week 8 guidance is largely about feeling anxious and stressed, and its advice is not to sit with it alone. Telling your midwife is a legitimate use of the appointment, not a distraction from it.

Is 8 weeks pregnant 2 months or 3 months?

Week 8 is the last week of month 2. At the end of this week you are two months pregnant, and week 9 begins month 3 — the final month of the first trimester.

There is no official weeks-to-months map. A calendar month averages about 4.3 weeks, not 4, so 40 weeks is a little over nine months — and two apps can disagree about which month you are in. The most widely used mapping:

• Month 1 — weeks 1 to 4
• Month 2 — weeks 5 to 8
• Month 3 — weeks 9 to 13
• Month 4 — weeks 14 to 17
• Month 5 — weeks 18 to 22
• Month 6 — weeks 23 to 27
• Month 7 — weeks 28 to 31
• Month 8 — weeks 32 to 35
• Month 9 — weeks 36 to 40

Your maternity team will not use months. Everything is booked by week and day — "11 weeks and 3 days" — because a few days change what is offered.

Miscarriage risk at 8 weeks

Week 8 is the second evidenced milestone, and a meaningful one. A study of over 300 women with a history of recurrent miscarriage found that seeing a heartbeat at 8 weeks gave a 98 per cent chance of the pregnancy continuing, up from 78 per cent at 6 weeks.

One caveat almost never stated: those heartbeat figures come from a study of over 300 women with a history of recurrent miscarriage, so their baseline risk was higher than average. For most people the equivalent numbers would be at least as reassuring.

More broadly, Tommy's cites research showing that once a pregnancy passes 6 to 7 weeks with a heartbeat, miscarriage risk drops to around 10 per cent, against a 10 to 20 per cent estimate for early pregnancy overall. Most miscarriages happen in the first 12 weeks, and risk falls dramatically after that.

You will find week-by-week miscarriage percentage tables all over the internet. Tommy's, which funds the UK's national miscarriage research centre, says openly that beyond the well-evidenced drop after 12 weeks, reliable week-by-week risk research does not really exist. We give you what is evidenced instead.

If you have a scan this week, a heartbeat at 8 weeks is genuinely reassuring information, and it is reasonable to let it reassure you.

The most common cause of early miscarriage is a chromosomal problem that happens by chance. Not lifting something, not a glass of wine before you knew, not stress or exercise. Tommy's states it directly: miscarriages very rarely happen because of something you did or did not do.

Is it safe to fly at 8 weeks pregnant?

Yes, in a straightforward pregnancy. The RCOG is unambiguous: occasional air travel is not harmful in an uncomplicated pregnancy. There is no evidence that cabin pressure or humidity harm you or the baby, and no evidence that flying causes miscarriage, early labour or your waters to break.

At 8 weeks there is a scheduling question as well as a medical one. Your booking appointment is due between weeks 8 and 12, and your dating scan between 8 and 14 weeks. If a trip would push either out, call the maternity service before you book rather than after.

The RCOG notes most obstetric emergencies happen in the first and third trimesters, and suggests a reassurance scan before flying if you have an increased chance of miscarriage or ectopic pregnancy. At 8 weeks a scan can confirm both location and heartbeat.

The risk that is real: blood clots

Pregnancy raises deep vein thrombosis (DVT) risk from the earliest weeks. ACOG puts it plainly: any travel of four hours or more — car, train, bus or plane — doubles DVT risk, and pregnancy adds to that. Under four hours the RCOG says you are unlikely to need special measures. Over four hours:

• Loose clothing, comfortable shoes, an aisle seat, regular walks about the cabin
• In-seat exercises roughly every 30 minutes
• Water steadily; cut down on caffeine
• Graduated compression stockings — not ordinary flight socks, and sized for you by a midwife or doctor

With other clot risk factors you may be advised to have heparin injections around the flight.

Practical points

• No airline restricts travel this early — cut-offs sit around 36 to 37 weeks for one baby, 32 for twins.
• Check what maternity and emergency care exists at your destination.
• Tell your insurer you are pregnant; cover should include pregnancy-related care.
• Some travel vaccines and anti-malarial tablets are unsuitable in pregnancy; travel to Zika areas is not recommended.

When to call your midwife or doctor

Early pregnancy is full of sensations that turn out to be nothing. These are the ones worth a phone call.

Get emergency help now

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand) or go to an emergency department if you have bleeding with any of the following, which the NHS lists as needing immediate assessment:

• Severe abdominal pain you cannot concentrate through
• Pain in the tip of your shoulder
• Feeling sick, faint or dizzy, or losing consciousness
• Heavy bleeding that soaks through a pad quickly

Sudden sharp abdominal pain with dizziness, faintness or looking very pale can indicate a ruptured ectopic pregnancy, needing same-day surgery. Around 1 in every 90 UK pregnancies is ectopic, and the NHS notes symptoms usually appear between weeks 4 and 12 — where you are now.

Call your midwife, early pregnancy unit or health line today

• Light bleeding or spotting, with mild or no pain
• One-sided pain low in your abdomen or pelvis
• Brown, watery discharge that is new for you
• Pain when you pee or open your bowels
• You cannot keep food or fluid down for 24 hours, your urine is very dark or absent for 8 hours, you feel severely weak or faint, or you are vomiting blood or losing weight — the NHS triggers for pregnancy-sickness help, which is treatable

You do not need a booking appointment first, and you do not need to be certain something is wrong.