The first trimester of pregnancy covers weeks 1-13, the first three calendar months of your pregnancy. You may not even be aware that you are pregnant for at least half this time.
The start of your period is a time marker for when ovulation occurs. This is why the first week of pregnancy is counted into your first trimester, even though you are still having your period. Most women ovulate sometime around 14 days from the first day of her last period, although the time varies depending on the length of each woman’s individual cycle.
Gestational age is the age of the pregnancy in weeks since your last period. Throughout this series, we will be referring to your baby’s gestational age, as most information around pregnancy does this as well.
How you may feel
By the end of the first trimester most women have had their pregnancy confirmed. If you haven’t made an appointment to see a midwife or doctor yet, now is the time. Some of the early pregnancy signs are discussed in week 6, but here are general indications:
- Breast changes including tenderness, tingling, increased sensitivity and a darkening of the areola (the skin around your nipple).
- Needing to wee more frequently than normal. This is because of the increased blood volume, as well as your womb placing pressure on your bladder.
- Feeling tired, not having any energy and wanting to sleep a lot. You may feel dizzy or light-headed because of the changes in your blood sugar levels.
- Feeling nauseous and having morning sickness, which might not be limited to the early part of the day.
- Being moody and easily irritated. You may cry easily and not be as even-tempered as you usually are.
- Feeling anxious about the possibility of miscarriage. This is very normal and most commonly occurs in the early weeks. So by the time you progress to the end of your first trimester, you should be feeling a bit more relaxed.
How you may look
- At 12 weeks your womb will start to lift out of your pelvis and a small bump can be visible in your lower tummy. You may start to show earlier if you’ve had a baby before.
- Your breasts may increase in size, so be prepared to buy new bras.