Why does my period come different times each month?
you cant have it the same day every month., or else you would have to have a 31 day cycle some months, 30 day cycle other months, and 28 day cycle in febuary. Count the number of days from the start of one period to the start of the next. That is the length of your cycle. If you are regular, that number will remain the same for each period(or maybe vary by 1 day)….and you will alway know when to expect it.
Menstrual periods are not always exact on the date. Depend on hormonal, emotional, light exposure, exercise etc. In general the leght of the menstrual cycle is between 24 to 30 days. The norm is 28 days. So you will find that it never fall on the same date. It will came short by one to three days always,sometimes a week. The best way to get and approximate day for your first day of period is to keep a calendar for at least a year. the fact that you have menses is the probable proof that you ovulate and are fertile. If your cycle is too irregular and fail for more than 3 months and menstrual flow is too heavy(more than 7 days, more than 6 pads per day), then you need a visit to the gynecologist.