Your body starts preparing before pregnancy exists
The menstrual cycle is a coordinated monthly system between the ovaries and the uterus. Even before pregnancy happens, the body starts growing an egg and building a thicker uterine lining.Menstrual Cycle: Why a Period Happens
One egg gets chosen. The rest fade away.
Early in the menstrual cycle, several follicles begin developing in an ovary, but usually just one dominant follicle fully matures. Around day 14 in a typical 28-day cycle, that follicle releases an egg.Menstrual Cycle: Why a Period Happens
