Doctors calculate your due date from the first day of your last period. So in week 1 you’ll still be having your period.
Ovulation usually happens at the end of week two. An egg is released from the ovaries into the fallopian tubes, where it is fertilised.
By now your egg has been implanted with sperm, and it’s possible that you could see a tiny bit of spotting – known as implantation bleeding.
You may experience a change in your sense of taste and you might start craving particular foods, or suddenly dislike things such as alcohol or coffee.
Already the heart begins to beat and on an ultrasound you can differentiate between the head and the tail.
By the end of the week your baby will be 4-6 mm Crown to Rump (CR) – about the size of a small bean.
The ears, eyes, nose and internal organs are developing and the baby is moving about in the amniotic sac.
You produce more blood during pregnancy. This and an increase in hormones can cause you to see bleeding gums occasionally.
Facial features such as the nose and mouth are developing, but the eyelids will be closed until around 27 weeks.
All the vital organs such as the kidneys, liver and lungs, are now in place and begin to grow and develop rapidly.