6 Answers

It's been known to happen. Abstinence is still the only birth control that is 100%. Have him use a condom for double protection but even condoms have been known to fail. 

Yes as Colleen and jhhartan says and certain other drugs. You have to get Family Planning Advice about which contraceptive is suitable for you and they will also explain this issue.

taking antibiotics while on "the pill" can make the pill useless...

Abstinence is still the best way to be sure.

you never know but its good if u think u are you need to ask a doctor or take a test . also there could be a chance that you could depending if you and your partner are wearing protection

thanks everyone:) and i didn't know bout that antibiotic thing. and no im not preg. it was just a random question