So I got bronchitus and a sinus infection was put on antibiotics for 10 days (my period started on day 3 of this course and only lasted 3 days which I figured was normal because I was so sick), then i got switched to a different antibiotic for 10 days (was not getting any better) , finished the 20 day course on Monday night. I'm on birth control pills (I know antibiotics mess with the effectiveness of BC) and my SO and I had unprotected sex last night. According to my chart I'm 3 days post fertile window and with only a 3 percent chance of getting pregnant. But what I'm wondering is could I still get pregnant. We aren't TTC and it wouldn't matter either way, I'm just curious.