Took postinor 2 in two consecutive months and my period was always a week earlier, now it's delayed for the third month and i didn't take it...

Typical : Emergency birth control 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 emergency contraception is not rare. Always check a pregnancy test after using and see a doctor to start a better form of birth control.