I don't know how valid this is but I've heard that you should avoid taking pain medication as much as possible for menstrual pain. There was some inconclusive research done stating that pain meds may affect fertility. I used to pop a Motrin every 4-6 hours during my period but have cut back to one pill on day 1 of period only. I try using home remedies instead but sometimes my cramps are too much to tolerate.