Do you have really painful periods? I would go see a gynecologist to rule out Endometriosis or Adenomyosis.
I'm in the same boat as you! I actually only started getting my period about a year and a half ago (I'm 18) but since the first one I've been getting excruciating, debilitating pain with some clots (I believe this is partly what causes the pain, especially when the clots are biggish - the cervix has to widen to let them through and it's almost like early labour pains!!).
I went on the pill too (Yaz) but it didn't help me at all, except to regulate my periods (I suggest skipping 3 months at a time - that was a bit of a lifesaver for me). I would also suggest taking anti-inflammatories the day you're due to start. Aspalgin works quite well for me (it has codeine in it). Also, a hot wheat bag is always comforting.
Hope you feel better soon!