The chances of getting pregnant while on birth control depend on the type of birth control and whether it is used correctly. Birth control pills are 91% effective with typical use, meaning that about 9 in 100 people may become pregnant in a year of taking it. However, if taken perfectly, birth control pills can be 99% effective at preventing pregnancy. Other types of birth control, such as injections, patches, and vaginal rings, have similar typical use effectiveness rates of 7-9% . It is important to note that no method of birth control is 100% effective, and certain factors such as missing doses or taking medications that interfere with birth control can increase the risk of pregnancy. It is recommended to use additional protection, such as condoms, to reduce the risk of sexually transmitted infections.