This is the Embryonic Stage. There are a lot of different developments going on for the major organs and basic anatomy. In the beginning weeks, there are three distinct layers, each later forming different sets of structures - Skin, hair, teeth, sense organs, brain, spinal cord, digestive system, liver, pancreas, respiratory system, muscles, bones, blood and circulatory system. Towards the later weeks, eyes, nose, lips, teeth and rapid head + brain growth.
Photo Credit: embryo.soad.umich.edu