My last period was 26 Aug 2012. For about two weeks i ve been cramping on my left side of my stomach. Sept 30, I started to see blood on the tissue everytime i wipe myself. I don t have any discharge ,itching burning while urine. I went to ER on Sept 30, but my test for UTI & STD came back negative but the Doctor prescribed me Vibramycin and discharge me with pelvic pain . Im still cramping, i noticed for the last two days after I use the restroom I drop about 3 drop of blood in the toliet. i been feeling nausea for some days but i threw up today after a hour of taking my antibiotics. What could be wrong with me.