If you douche after intercourse, the chances of pregnancy are reduced, mainly because douching causes a large amount of semen to pass out of the vagina. However, if a small amount of semen enters the uterine cavity, it can also cause pregnancy. So if you use douching after intercourse to prevent pregnancy, it is not reliable and may fail. If contraception is not used, the emergency contraceptive pill can be taken orally within 72 hours after intercourse to remedy the situation, which will significantly reduce the chance of pregnancy. Although the emergency contraceptive pill is effective, it does not achieve 100% contraception, so someone taking the emergency contraceptive pill still has the possibility of getting pregnant. So if you are not planning to get pregnant, you can use condoms to give birth control.