Before 3 days i had an unprotected sex and i take 2 tablets ecp. now i am not bleeding what does it mean?

Typical with Plan B: Plan b essentially disrupts the normal menstrual cycle by blocking or delaying ovulation. That it is how it works and why it is so different than a medical abortion. Irregular bleeding after taking Plan B is common but not necessary. Always check a pregnancy test after using Plan B and see a doctor to start a better form of birth control.