If pregnancy is to be achieved, it is recommended that sexual relations be avoided during the days of menstruation. Because menstrual bleeding can conceal cervical mucus in a short cycle, abstaining allows for positive identification of the time mucus begins, which will help you identify the most fertile mucus.
Another reason for abstaining during menstruation is that recent medical evidence seems to indicate that sexual relations during the days of heavy menstrual flow may be responsible for the development of endometriosis in some women.
