The menstrual cycle is counted from the beginning. The first day of a woman’s bleeding is the beginning of her menstrual cycle, and the interval between the first day of two adjacent menstrual periods is one menstrual cycle. 1. Duration of the menstrual cycle: Normal menstruation is cyclical, and a woman’s menstrual cycle usually lasts from 21 to 35 days, with an average of 28 days. 2. Symptoms of the menstrual cycle: A menstrual cycle consists of the menstrual period, the proliferative period and the secretory period. (1) Symptoms of the menstrual period: generally there are no special symptoms during the menstrual period, accompanied by cyclic ovulation of the ovaries, and cyclic changes in the secretion of estrogen and progesterone by the ovaries, which may be accompanied by cyclic shedding of the uterine lining and bleeding. Some women may have lower abdominal distension, diarrhea, headache and other symptoms. (2) Symptoms of proliferative stage: This is the stage of follicular development and maturation. (3) Symptoms of secretory phase: This phase is equivalent to the luteal phase, when the uterine lining is thick and fluffy, which is conducive to the implantation of a fertilized egg. If you have any discomfort during your period, we recommend you to go to the hospital in time for examination and treatment according to the doctor’s instructions.