Normal sexual life without contraception for more than a year without pregnancy, consider the possibility of infertility, even if the period is very accurate, sometimes can not conceive, the reasons may be as follows: 1, endometrial problems, such as endometrial polyps, uterine submucosal leiomyomas, may lead to non-pregnancy; 2, whether there is a mature follicle discharge, you need to monitor the ovulation; 3, to check the bilateral tubal patency; 4, immune aspect checking; 5, female hormone aspect checking; 6, sperm quality checking and so on. Therefore, even if the menstrual period is accurate, but one of the above reasons is abnormal, it will also lead to non-pregnancy.