Your doctor can prescribe a medication that you start a couple of days before your period that helps you not cramp so badly. I don't remember what it's called. It's the same medication (in a way lower dosage) that they give to women to delay labor.
Also I've found that taking a potassium and magnesium supplement helps. They help with muscle cramps in general. I also would drink a lot of water and use a heading pad (they even make really awesome ones that stick to the inside of your pants so you can move around). A hot bath can help too.
I used to have TERRIBLE cramps with my period and so I did all that.. they were still so bad that I couldn't move and they made me feel nauseated so I switched my birth control to the shot - no periods. Talk to your doctor about the cramps. Not only are they inconvenient but they can also indicate another problem.