By the time you're eight weeks pregnant, the baby is called a foetus, which means 'offspring'.
The legs are lengthening and forming cartilage too. The different parts of the leg aren't properly distinct yet – it will be a bit longer before the knees, ankles, thighs and toes develop.
The foetus is still inside its amniotic sac, and the placenta is continuing to develop, forming structures called chorionic villi that help attach the placenta to the wall of the womb. At this stage, the foetus still gets its nourishment from the yolk sac.
Conception usually takes place about two weeks after your last period, around the time that you ovulate (release an egg). In the first four weeks of pregnancy you probably won’t notice any symptoms. The first thing most women notice is that their period doesn't arrive. Find out about the signs and symptoms of pregnancy.
By the time you are eight weeks pregnant, you will probably have missed your second period. However, some women experience a little bleeding during the early weeks of pregnancy. Always mention any bleeding in pregnancy to your midwife or GP, particularly if it continues and you get stomach pain.
Your womb has grown to the size of a lemon by the time you are around seven or eight weeks pregnant. You're probably feeling tired. Your breasts might feel sore and enlarged, and you are probably needing to pass urine more often than usual.
Some pregnant women start to feel sick or tired, or have other minor physical problems for a few weeks around this time. Most women stop having morning sickness and start to feel better by the time they are around 14 weeks pregnant.