Birth control are medicines and devices that help people not get pregnant when they do not want to. They work by stopping a woman's eggs from being fertilized by a man's sperm, which is needed for a baby to be made. One common way to use birth control is a pill. The pill is taken every day and it releases tiny amounts of hormones that prevent a woman's egg from being fertilized. Other birth control methods include things like IUDs (a small device a doctor puts inside the uterus) and condoms (a thin cover that is put over the penis). These work in different ways to prevent the sperm from reaching and fertilizing the egg.