Question: how likely is it to get pregnant on birth control and plan b?
Answer: If you take the pill within 72 hours after you've had unprotected sex, levonorgestrel can reduce the risk of pregnancy by up to 87% if taken as directed. If you take Plan B One-Step within 24 hours, it is much more effective. But you should know that Plan B One-Step is not as effective as regular contraception.