First of all take some Calcium before and after you start... and then take some potassium.... then get you a heating pad... put it on your stomach.. And, also maybe take some Midol... Hope this helps you! Feel Better!
Lay down with a heating pad (set on low) on your belly, and take a regular dose of an over-the-counter pain reliever. Midol is supposed to help with period problems, but read the ingredients list, and if all it is is acetaminophen or aspirin, buy a generic and save yourself some money.
Exercising makes them go away, which is funny because they they hurt so badly that exercising is the last thing anybody wants to do :P but if you can force yourself to go for a run, you'll feel much better in terms of cramps.