Suggest Medication For Stomach Pain And Cramps During Periods

My stomach has been hurting for three days now, It started on Friday night and it alternates between feeling like I'm going to be sick and cramps. Saturday was the only day I threw up at all because of it. I can't sleep at night because of it and I had to stay home from school today. I'm fifteen and I did get my period on Sunday, but it never hurts like this. I also just recently got over a cold and was taking Nitetime medicine for it. I know for a fact that I'm not pregnant. I have been drinking liquids to keep hydrated, and I've been able to eat bland things such as pretzels (I've been afraid to eat anything else.) What's wrong with me and what should I do?