The morning after pill is a high-dosed progesterone pill intended to be taken within 72 hours after unprotected sex to prevent pregnancy. However, it may or may not prevent pregnancy depending on where you are in your cycle.
There are three ways it can work:
- Prevent ovulation subsequently preventing fertilization
- Affect the lining of your Fallopian tubes to prevent sperm from reaching the egg, therefore, preventing fertilization
- Irritate the lining of your uterus making it difficult/harder for the fertilized embryo to implant in your uterus