A menstrual cycle is measured from the first day of menstrual bleeding (Day 1) by counting the number of days until the next menstrual bleeding. From day 1 of the bleeding to day 1 of the next time of bleeding is "the menstrual cycle". An average menstrual cycle lasts about 28 days, but it' s normal to have menstrual cycle that lasts from 21 to 35 days. Problems conceiving may originate from both partners, so diagnostic examinations should be done by both...although it's easier to start with the man's diagnostics. The tests are less complicated and take a relatively short amount of time.