Menstruation is one of the outward signs of reproductive maturity. Normal first menstruation should be between the age of 9 to 16 years old; menstrual cycle refers to the interval between the first day of two menstrual periods, usually between 21 to 35 days, an average of 28 days; menstrual period refers to the duration of menstruation, usually between 2 to 8 days; menstrual flow is between 20 to 60 ml, menstrual flow of more than 80 ml, for excessive menstruation; menstruation can be accompanied by some women with mild discomfort. Is your menstrual behavior consistent with the above, if not, it means that your menstruation is not normal, you need to go to the hospital for examination.