Dr Bunsen says "There are easier forms of contraception for the mosquito, than pill form. Usually abstinence is the best form of protection, however there have been reports that immaculate conceptions have taken place in the past. Although she was blatantly lying through her teeth."
It probably depends on which contraceptive and which Malaria tablets you are taking. I would trust a GP rather than someone on NSC - unless they were a GP of course.