The premenstrual syndrome (PMS) are real physiological manifestations which occur as physical discomfort about one or two weeks before the occurrence of periods in women.
A rationale for existence of PMS is the changing levels of hormones during the menstrual cycle in women. These hormonal changes have significant impact on the physiological and psychological aspects, thus leading to PMS.
Indulging in sex during menstruation would evoke negative feeling for most individuals. This is influenced largely due to personal preferences and opinions though there is no scientific basis to discourage sex during menstruation. These feelings would have developed due to cultural, religious, and traditional views on sexuality which have created a strong impression in one's mind.
Being in a developed society, the early messages received about menstruation were adequate for understanding the phenomenon and for preparedness. Similarly, the information and guidance received during the growing-up period also were informative.