Final answer:
The first two weeks of prenatal development after conception are known as the germinal stage, characterized by rapid cell division and the formation of a blastocyst.
Step-by-step explanation:
The first two weeks of prenatal development after conception are known as the germinal stage. During this stage, rapid cell division occurs and the conceptus goes through early cell divisions and stages such as the zygote, morula, and blastocyst. The blastocyst then implants in the uterus to become an embryo.