Menstrual cramps, properly called dysminorrheya. Typically have no underlying gynecological problem, and tend to get better as we get older.
There is a general belief that menstrual cramps get better after pregnancy. I had just three periods between weaning my secod child and getting pregnant the third time, and these menstrual cramps were worst in my life. Not that we decided to have a third child because of that. Now it's addmittedly better that in my teens. Menstrual cramps get worse if is woman cold or stressed out. Mild exersise, like walking, stretchig, and yoga, seem to help. Over the counter painkillers help to a degree. I prefer Ibuprofen.
My theory is that at least part of the menstrual cramps discomfort comes from your digestive system. A uterus is contracting, forsing out material it doesn't need, and dygestive system contracts as well, because it is same type of mustle under same hormonal control. Now, is one has bowels acting as if one had diarrhea, and she actually doesn't, it must hurt. So, foods high in dietary fiber must help. I used to have bad menstrual cramps. I tested my theory by eating enourmous amounts of prunes and washing them down with kefir. I still have menstrual crups, but guess what -- not as bad! I keep my head ache, and still feel as if I better slept three more hours. Or days. And my mood swings are with me. But at least my menstrual cramps are not as bad, and I like prunes and kefir anyway.