im 26 now but i was 13 when i got my period and not long after i started having such severe cramps that i would get sick and not even go to school. my cramps would start a few days before my period and last until the last day of my period. i found out when i was alot older that it is called Dysmenorria (i think i spelled that wrong lol) it is basically very severe cramps. i did get put on birth control at 21 to help stop it but it actually did not help. then last year i was on another one to help and that made things worse. i still have it, nothing helps much, but after i had 2 kids it seems to only be every other period now. most of the time anyway lol. i wish i could help you more. it sounds exactly like what i have. if u can ask ur doc for a prescription of tylenol 3, that seems to help alot but some docs wont give it out because it is a combination of tylenol and a narcotic. given ur age they may not