My back severly hurts?

I got my period today and my back hurts more than it ever has! earlier today i got down on the floor and started crying. instead of cramps every period i get back pains! i cant take swallow pills so i take chewable. my mom went to pick up some meds for me and my back still really hurts. is there anything i can do to get the pain to go away? it'll get faint then POW! it hits me like 1000 rocks. and doesn't go away for like an hour. im going back to school shoping at the mall which takes lots of walking and my back hurts when i walk! any tips!!!!!!