This week your baby is about 3.1cm from head to bottom and weighs less than 4g....he may be small but he is very active....swallowing liquids and kicking with his feet....his vital organs like liver, kidney, intestine, brain, lungs are fully formed and make up almost half of his head....prominent....and if you hold him look, you will notice the interesting details do....nails and fluffy body hair like peach fuzz....Your uterus is now the size of a grapefruit and may even be palpable above the pubic bone....Brain: Your baby's forehead is prominent and contains the developing brain and sits on top of the head....yolk sac: His liver no longer needs blood cells..atrophy...slow....Fingers: The fingers have completely separated and the nails are just beginning to grow...