I know that in CFers, birth control is less effective, because of how we absorb things, etc - but I don't have any statistics. I know you say you're not 'active', but if/when you decide to - make sure that you're using 2 forms of birth control, i.e. the pill and condoms. I know that with CF its harder to get pregnant, but there have been CFers who have accidentally gotten pregnant even on the pill.