I'm looking at my BCP case right now...there's a huge red sticker saying that antibiotics will decrease the efficacy, and to use additional contraception. I thought this was standard knowledge--the one time in my life I took an antibiotic (the parents kept me away from them for the longest), the doctor and the pharmacist were like, "use a barrier method." Which was funny because I wasn't on BCP at the time.
I hope you feel better.