What is happening in week 12
Doctors count pregnancy weeks from the first day of your last period, so week 12 sits in the first trimester (up to the end of week 13). That is about 28 weeks to go until week 40, and about 2.8 months by a rough conversion. By week 12 the baby is about 5.4cm long and the heartbeat can be seen on a scan.
Your baby
The NHS guide gives 5.4cm from head to bottom, compared with a plum. Internal organs and muscles have grown, the skeleton is hardening from tissue into bone, and the sex organs have formed, although most scans cannot tell the baby’s sex yet.
Your body
The placenta has probably taken over feeding the baby, so hormones may settle and sickness may ease. Your waist may thicken and breasts may grow. As sickness eases you may feel hungrier, but you do not need to eat more for the baby.
This week’s to-do
- Attend your dating scan; the NHS says it is usually done at 8 to 14 weeks, and its scan page says 11 to 14 weeks.
- Many women tell their employer after the first scan; you can decide when to share the news.
- Start thinking about contraception for after the birth.
When to call
Call your doctor or hospital if you have any bleeding, or if low mood or anxiety does not ease.
Chaitanya Hospital in Kadapa, near RTC Bus Stand, Simhapuri Colony, provides delivery and emergency care 24/7. Our antenatal check-ups team can answer questions about your own pregnancy.
Use the week-by-week guide to jump to your week, or the due date calculator to work out your dates. Timings for scans and tests come from NHS guidance in the UK and can differ from your doctor’s schedule, so always follow your own doctor’s advice. This page is educational and not a substitute for a doctor.
Sources
Text on this page is paraphrased from the sources above. Sizes are averages and vary between babies.