What Signs Indicate Being Safe After Having Unsafe Sex On Taking Unwanted72?

Hi. Sir/madam,I had sex with any protection n 2, 3 times intercourse held . My quetions are How much time taken for bleeding after taken unwanted72 ??? its my gf 5th days and bleeding is not coming. I hd sex on 2nd march n after 9 hrs later she had taken pills unwanted 72 is there any chance of pregnancy? And its not occurng her preiods da last date of her preiods is 31 jan.