Family Planning Plus

If you are correctly using a hormonal method of birth control (pill, patch, ring, shot, implanon, or mirena IUD), and you have been using it for at least seven days before the incident occurred, pregnancy is highly unlikely. When used perfectly, hormonal methods of birth control are over 99% effective. They work by preventing ovulation (the monthly release of an egg). Without an egg, there is nothing for the sperm to fertilize.