L.B.
My period symptoms changed with each child (3). I finally found using supplements eased PMS and other discomfort, like an extremely heavy flow. It takes some patience because it is a cumulative effect~1200 mg of Omega 3 and vitamins. Mega doses of vitamin A, E & C made a big difference but you must be sure there is no chance of getting pregnant.
Vigorous exercise (like running) 4+ times a week improves PMS & menstruation like nothing else.