This week marks the beginning of the embryonic period. From now until 10 weeks, all of your baby's organs will begin to develop and some will even begin to function. As a result, this is the time when she'll be most vulnerable to anything that might interfere with her development.
Right now your baby is an embryo the size of a poppy seed, consisting of two layers: the epiblast and the hypoblast, from which all of her organs and body parts will develop. (From Baby Center )
How me and Graeber #3 are: