Im on birth control although I began taking antibiotics recently. The first day I got my antibiotics I took,one at work before I came ho my normal medecine in the morning. me. That night, my boyfriend and I had unprotected sex, and once again in the morning. We both forgot until I was taking my medicine in the morning. He told me not to worry since I had only taken one dose. Ive been cramping very very bad for two weeks and my period just came four days late. I started just spotting and the next day was clotting. Its very painful cramping and I noticed the blood was bright red which seemed odd. I took a pregnanxy test the first day I was late and it was negative. Im thinking miscarriage or