How likely is it to get pregnant by skipping a couple of days of your birth control?

Pretty High: Birth control works by two mechanisms - preventing ovulation (an egg being released from the ovary) and by keeping cervical mucous thick (harder for sperm to get to egg). Missing one pill raises your chance of conceiving to 5-10%. Missing two consecutive pills to 20% - close to the chance of getting pregnant using no birth control at all. Pills work great - but only if you're a consistent!