I've been on the pill, Cilest, for over a year now. Recently I was prescribed a course of antibiotics, trimethoprim, to treat a UTI. I was not told by my doctor that they would reduce effectiveness of the pill, so continued to take the pill as normal. A week after the course ended, (today), I had unprotected sex with my boyfriend. I have taken the pill normally this month the only change being the addition of the antibiotics. Is there a chance I'm pregnant? If so should I take the morning after pill tomorrow to be sure I'm not? Or is that just me being overly paranoid? Thanks for any advice :)