What Cause Diarrhea On The First Day Of Periods?

I started my period this morning. I took BC powders. Later IBUPROFEN. Later for first time ever Midol with acetaminophen. Every since everything liquid or food immediately comes straight out as diarrhea. As im eating my stomach is pushing. Is it the Midol? Should I be worried? My stomach is aching now. Cant eat or drink it will come out I think I have hemorrhoids now. Is this something I should be concerned enough to go to emergency room? Or will it go away quick? Please help this sucks!!