Menstruation is affected by changes in the endocrine hormones in each person’s body and also by the hypothalamus in the body, including the pituitary gland, which produces the menstrual cycle. The normal cycle is 25-30 days. If the patient has a 37-day menstrual cycle, it is considered a normal cycle, which does not mean that everyone’s menstruation is a good day, as long as the fluctuation range of each menstrual period is around 37 days is considered a normal cycle. Because there are some people who have a period once every 45 days, or even 50 days, 2 months, or 6 months, this will not affect pregnancy as long as there is normal ovulation, so it is recommended not to worry and anxiety. At the same time, if you get your period once in 37 days and the next one in 45 or 50 days, you may have irregular menstruation, so you should check your endocrine hormones on an empty stomach from the second to the fifth day of your period to regulate your cycle.