The embryo starts to form a head and body. The optic vesicles, a mouth opening and the auditory vesicles of the ears make it possible to identify the embryo’s face.

There are buds for the formation of the arms and legs. The heart is clearly discernible as a bulge and the blood vessels now contain proper blood cells. The intestinal system, lungs, liver, pancreas and thyroid are also developing. The embryo is growing rapidly: it is now twice as large as it was at the start of this week.

Now you can clearly notice the physical changes taking place as a result of the pregnancy. The muscles of the cervix and womb are relaxed, the mucus membrane on the cervix and vagina has taken on a bluish colour and the uterus is becoming larger. Increased blood flow to the uterus may cause a light pulling sensation on the lower part of your belly.

You will probably also start experiencing some of the unpleasant side effects of being pregnant. Your body may react to the hormonal changes with nausea, fatigue, loss of appetite, constipation, a frequent need to urinate, difficulty sleeping and other symptoms. They are all a normal part of any healthy pregnancy – and if you don’t experience any of the above, even better.

Your baby is about the size of a pea.

Baby Entwicklung Schwangerschaftswoche Erbse 3