Day 1 (Menstrual Cycle Start)

Day 1 of the menstrual cycle marks the start of menstruation, when the uterus sheds its thickened lining, resulting in bleeding. This phase is regulated by a decrease in hormones like estrogen and progesterone, signaling the body that an egg was not fertilized. The shedding begins with menstrual flow, lasting typically 3-7 days. During this time, the body resets its hormonal levels, preparing for a new cycle. It's a natural, healthy process that prepares the reproductive system for potential pregnancy in the coming weeks.