i've always had terrible periods, so i was on the depo provera shot for 8 years or so until i ended up in the emergency room with blood clots in both lungs. then they put me on blood thinners and took away my birth control which made my periods even worse, so my ob/gyn was cool enough to do an endometrial ablation (word of warning though, the procedure is not reversable, and you will not be able to have kids after having it) to control the heavy bleeding. unfortunately, i still have cramps occasionally though, and i've found that vicodin/lortab doesn't work that well for me and anti inflammatories are out of the question because of the blood thinner. however, odd as it seems, antihistimines seem to help. for a lot of people, they have an overall relaxation effect, and for women on their periods, we apparently have higher than normal levels of histimine in our bodies, which make us feel pain more acutely (it was explained to me that way by my nurse, and my massage therapist, so i guess there's something to it). also, they make these warming pads, that have sticky stuff on one side (check the feminine protection/hygiene area of a drugstore or ask the pharmacist) that you can stick across your lower back or abdomen and wear them under your clothes. they stay warm for 6-8 hours each and they're disposable. they really seem to help and they're a non-drug alternative.
other than that, just stick with whatever you can do to make yourself more comfortable 'til it's over. and do check with your doctor if this is something new/unusual for you, just to rule out any other problems.