Intercourse during menstruation may lead to infertility, because the human body’s resistance is poor during menstruation and there is more chance of reproductive tract infection. Intercourse at this time may lead to endometritis and pelvic inflammatory disease, and in serious cases, it may lead to tubal blockage and uterine cavity adhesions, which will form infertility. Once infertility occurs, patients should check whether there is any problem with the endometrium, whether there are uterine adhesions, and whether the fallopian tubes are patent. A tubal imaging can be done to see the condition of both fallopian tubes. If the fallopian tubes are open, the male partner should be further checked for problems, and ovulation monitoring should be done to see if there are problems with ovulation that cause infertility. The causes of infertility are complex and involve many aspects. If infertility occurs, the causes of infertility should be investigated in many ways.