The first two weeks of the human development are called the preembryonic period. This period begins with the fertilization. Fertilization is the beginning of the pregnancy and can be considered as the beginning of a new life.
In order to have successful fertilization, several events have to be take their course (e.g. gametogenesis). Female gamete (oocyte) is produced during the menstrual cycle and expelled during the ovulation. During each ovarian cycle, only one follicle with an oocyte reaches full maturity. At the 14th day in an average 28-day cycle this follicle bulges on the surface of the ovary. Immediately before the ovulation, the oocyte and some surrounding cells (cumulus oophorus) detach from the interior of the follicle. Also, shortly before the ovulation the fimbriae of the oviduct start covering the surface of the ovary. During ovulation, follicle bursts and the oocyte is expelled into the uterine tube.