an average menstrual cycle is 28 days (first day of the cycle to the next menstrual cycle). however a normal menstrual cycle can range from 21 days to approximately 35 days. if your daughter is relatively young then this may be normal for her. some women do not regulate their menstrual cycles until their late 20's. the concern with very long cycles is that ovulation (egg release) may not be occurring which could cause infertility. there are several reasons for long cycles one of which may just be young age. your daughter should see a gynecologist just to make sure everything is okay.
my daughter's cycle is usually 36 days this month 26 days should i be concerned she is concerned about infertility?