question:

If a girl took 1st pill of postinor2 on the 2nd day afte unprotected sex, then 2nd pill 12hour. then less then 5hour she consumer the pill, she got did it again(unprotected sex).

Or more easy to understand:
If a girl took the Postinor2 before sex.

What will happen? Or what side effect to the girl? and does it help to prevent pregnancy?