I am on keflex for acne, as well as mononessa for bc, my dermo told me keflex would not interfere with the bc pills- is this true?

Conflicting studies: 1st of all, no oral bc is 100% effective in preventing pregnancy. 2nd, antibiotics can interact with bc and possibly reduce bc effectiveness. 3rd, study results are conflicting -- some said antibiotics use while on bc increases risk of pregnancy, others said they don't. Advice: if worried, use a 2nd method of bc such as condom (which can lower risk of contracting stds).