Some of the things I've tried in the past are; heating pads, Ibuprofin or Midol, and stretching. Even though I always wanted to curl up in a ball, I read that stretching helped and tried it myself and was surprised that it did. If you do any Yoga, try some of those positions. Blood clots are usually normal during the worst of your period if they are no more in a quarter in size and you are not soaking pads like every hour.
Also, if you haven't seen an OBGYN yet (I see you are 15), I would make an appointment.
Good luck to you and I hope something I recommended works :)