Height: 0.4 cmWeight: 0.2 g
My brain has begun to develop and the heart, which so far has been no bigger than a poppy seed, has begun to beat.
The abdominal cavity, chest cavity, spine and digestive system have begun to take shape whilst my tiny legs and arms begin to emerge. My jaw and tiny teeth can be seen. By the end of the week, my bloodstream is in full flow and you might be able to distinguish between my eyes, nose and mouth — if you could see me. The amniotic sac is developing, but so far it contains no amniotic fluid. The umbilical cord is also in the early stages of development, but it is still short and requires a little more strengthening in order to be able to withstand all the hitting and pulling I'll do later on in the pregnancy. The first few weeks are filled with a lot of rapid development, even if a lot of that activity might go unnoticed by mum at this stage.
I still receive nourishment from the yolk sac and will continue to do so until week 9-10, when the placenta takes over that role. If my mother was to ingest something not good for me, it wouldn't cause me any harm since most of my nutrition comes from the yolk sac until week 9-10. From the moment mother discovers she is pregnant, it would be in both of our best interests if she followed the food recommendations for pregnant women.