Yesterday my period shown up early right after I had my fertile window and right now I'm sitting on my bathroom floor feeling sick and nauseous.

Early periods have never happened to me before and a few hours prior I was literally sitting in the shower and blood was flowing out of me. This has never happened to me before and I don't know what to do. Right now.

Please help...F-16

EDIT: My period wasnt due for another 11 days.