The interval between the first and second period is usually 28-30 days, which is considered a normal cycle, but because each woman’s cycle is different, endocrine hormones will also have certain changes, it can be 40 or 50 days to have a period, but the most important thing is that every time there is such a long interval, it is also considered a normal cycle, and there is no need to be overly nervous. Some women deliberately use medication to regulate to 30 days, but when they stop the medication, they can still return to 40 or 50 days. 40 or 50 days is considered a normal cycle and will not affect their reproductive health or physical health. Some women have irregular menstrual cycles, such as 25 days this time and 40 days the next, which require ultrasound, including endocrine hormone blood tests, to analyze what is causing the problem, so that symptomatic medication can be used.