The unfertilized egg cell atrophies and is completely destroyed. The mucous membrane of the uterus deprived of hormonal nutrition gets separated and removed from the body along with blood, mucus and vaginal secretions. This is menstruation. The first day of menstrual bleeding is considered to be the first day of the menstrual cycle. In the first half of the cycle, when follicles mature in the ovaries and an egg cell grows in them, the ovaries actively produce estrogen hormones. Therefore, this phase is called estrogenic. In the second half of the cycle, the burst follicle at the site of the released egg cell begins to synthesize the hormone of corpus luteum which helps the uterine lining to prepare for the implantation of the ovum. This phase of the menstrual cycle is called corpus luteum phase. Immediately before the ovulation, when the uterus prepares to meet a fertilized egg, most women loom large. In the second half of the cycle, when the process of rejection and cleaning of the used and unsuitable material begins in the uterus, women can become more excitable and irritable, especially 2-3 days before the beginning of menstruation.