(OCP- Oral Contraceptive Pills)
The birth control pill works by stopping sperm from meeting an egg (which is called fertilization). The hormones in the pill stop ovulation. No ovulation means there’s no egg hanging around for sperm to fertilize, so pregnancy can’t happen. The pill’s hormones also thicken the mucus on the cervix. Thicker cervical mucus makes it hard for the sperm to swim to an egg — kind of like a security guard.
When used perfectly, the pill is 99% effective. But when it comes to real life, the pill is about 91% effective because it can be hard to be perfect and it canbe effected by other medications you are taking. So in reality, 9 out of 100 pill users get pregnant each year.