extremely painful back pain like labor while in period

i don't know why my this last periods i have gotten have been intense. i just got period yesterday and i started with strong back pain like my back was opening and the cramps were mild .. it felt like labor the pain got so bad i couldn't take it no more. I don't take any type of medication but this pain was so extreme my friend gave me two pills of midol and it did it's job. and gave me 4 more pills for later on. tomorrow I'm going to buy myself a packet and going to call my obgyn. but for now I'm freaking out why have i gotten my period this intense and if it's fixable.