A complete menstrual cycle is counted from the first day of menstruation until the first day of the next menstrual period. Normally, the menstrual cycle is counted as one month, but in fact it varies from person to person. The menstrual cycle calculation should include the time of menstruation, and some women only count the time when their period clears, which may be considered a shortened menstrual cycle. A menstrual cycle usually lasts from 21 to 35 days, with an average of 28 days, and it is normal to have one period at the beginning and one at the end of the month. What is a normal menstrual cycle? A normal menstrual cycle is a preliminary indication of a woman’s state of health. It can be analyzed from two aspects: the time of menstrual cycle and the time of menstruation. 1. Menstrual cycle time: The normal menstrual cycle is 28 days, occasionally early or delayed time not more than 7 days is considered normal, so the normal cycle of menstruation is not less than 21 days and not more than 35 days. The length of the menstrual cycle depends on the length of the maturation period of the follicles in the female ovaries, while the length of the luteal phase is the same, about 14 days. If the follicle development period is long, the menstrual cycle will be long, and vice versa, the menstrual cycle will be short. 2, menstruation time: menstruation time is the period, refers to the duration of the menstrual flow, the normal female period time is generally 2-8 days, an average of 4-6 days. If the menstruation is normally normal and there are no other obvious special triggers leading to early menstruation or delayed menstruation for more than 7 days and prolonged menstruation, you should consider whether you have a condition such as menstrual disorder. When menstruation comes, it is important to pay attention to menstrual hygiene, because women’s resistance is low during menstruation and they are easily infected. If you have symptoms of irregular menstruation, you should have a checkup to determine the cause and get timely treatment so that future conception will not be affected. The menstrual cycle, also called the ovarian cycle, is divided into four phases, including the follicular phase, ovulation, luteal phase and menstrual phase: 1. Follicular phase The follicular phase is from the first day of menstruation to the day of ovulation. During this period, the follicle stimulating hormone increases the concentration of estrogen hormone in the body, the follicles mature and the endometrium thickens. 2. Ovulation Ovulation is the process in which the egg cells are expelled together with the surrounding granular cells of the oocyte mound. The ovulation date for women is usually about 14 days before the next menstrual period. The luteal phase refers to the day after ovulation to the day before menstruation. The ovaries are influenced by luteinizing hormone, which secretes luteinizing hormone to maintain the thickened endometrium for the fertilized egg to lay. 4.Menstrual period The duration of each menstrual period is called the menstrual period, which is usually 2-8 days, with an average of 4-6 days. Generally, there are no special symptoms during menstruation, but during menstruation, due to pelvic congestion and the action of prostaglandins, some women may experience discomfort in the lower abdomen and lumbosacral area or painful contractions of the uterus, and may have diarrhea and other symptoms of gastrointestinal disorders.