
Your pregnancy is divided into three stages called trimesters.
- First Trimester: 0-12 Weeks
- Second Trimester: Weeks 13-27
- Third Trimester: Weeks 28-40

The first trimester
During these early weeks you may be feeling the same as usual and perhaps unaware that you are pregnant, however, inside amazing changes are taking place. If this is your first baby you may not begin to show until at least week 12 but if this isn’t your first you may start to show earlier as your belly may have been stretched from your last pregnancy.
You may notice changes in your body such as:
- a missed period
- a strange taste in your mouth
- achey breasts
- feeling sick
- feeling tired
- heightened sense of smell
- needing a wee more often
- a milky white discharge from your vagina
- light spotting of blood as the egg implants into the womb (see your doctor urgently if more bleeding occurs during pregnancy)
- tummy cramps
- dark patches appearing on your skin called ‘chloasma’ or the ’mask of pregnancy’
- bloating
- changes in the appearance and feel of your hair
By week eight your baby has grown to an impressive 16mm, roughly the size of a raspberry. Arms and legs are getting longer, and your baby is creating around 100 new brain cells every minute. It’s around now that your embryo officially becomes a fetus.

New changes in your body will be more apparent between weeks 8-12. Some people notice that their breasts have increased in size and pregnancy hormones are now racing around your body which may cause you to feel unwell and not yourself.
Try to rest when you can and ask for support from your family and friends. Your baby is growing at a fast rate and your body is working hard to support this speedy development.
It is around week 9 that the placenta is already getting prepared to give your baby its nutrients and oxygen Your baby has grown to 22mm in length, roughly the size of a strawberry, and facial features are now a little more recognisable. Hands and feet are developing along with internal organs such as the heart, brain, lungs kidneys and gut. Your baby’s genitals are also starting to form, but it will be a bit of a wait before you find out whether you are having a boy or a girl.

Around this time you will be offered your first scan, called the 12-week scan. The person who scans you is called a sonographer and they will estimate when your baby is due based on its measurements. This is called the ‘estimated date of delivery’ or EDD. Don’t forget to take some money with you as there is usually an option to purchase a scan picture of your baby.

The second trimester
You will begin to notice a small baby bump developing as your womb grows and moves upwards. For some, this is a nice feeling as you know you are actually starting to look pregnant. Any feelings of needing to wee more often should start to ease off now. You must talk to your GP if you notice any problems with your wee or bladder. If you experience any pain or burning when having a wee it could be a urinary tract infection. it is important to treat this infection quickly to reduce the risk of kidney infection.



Around this time you will be offered your 20 week scan. The 20-week screening scan, sometimes known as the anomaly scan looks in detail at your baby’s bones, heart, brain, spinal cord, face, kidneys and abdomen. The scan allows the sonographer to look for 11 rare conditions. More about ultrasound scans in pregnancy: Read more about ultrasound scans in pregnancy
At 20 weeks pregnant, you are halfway through your pregnancy. You may notice a dark line down the middle of your stomach. This is normal skin pigmentation as your stomach gets bigger to accommodate your growing bump.

The third trimester

At 40 weeks most of your baby’s development is complete. Their hair may continue to get thicker and their nails may grow more too. Weighing the same as a small pumpkin, your baby is ready to meet you. You may find your patience is getting low and as if time is dragging. If you have the energy, perhaps try fitting in a few last-minute treats and outings. Enjoy a meal out with friends, cozy up with a box set, or just enjoy some time with your partner.
Call your midwife or unit if:
Typical signs of early labour
- contractions or tightening around your bump
- a “show”, when the plug of mucus from the entrance to your womb comes away
- backache, period-like cramps
- an urge to go to the toilet, which is caused by your baby’s head pressing on your bowel
- your waters breaking
- your waters are smelly or coloured
Find out more about early stage of labour
