I'd advise drinking a lot more water before. You are going to want to replenish the blood you lost, and drinking a lot of water will help, as will things like juices. Soft drinks (Coke, Pepsi, etc) have caffeine, and caffeine will dehydrate you, as will chocolate. I find that Pamprin helps when I've been cramping up, too.
Anytime I think I'm perfect, I remember that my cousin lives on an island, and I've never walked over to visit her.