What Causes Delays In Menstruation?

Hi! Me & my boyfriend tryed to have sex we did it with a comdom he went a little inside of me it hurt so i told him to stop & that was aug 5, 2014 he putting it in again it broke thats when we stopped NO PER CUM or nothing . On aug 11, 2014 we tired again he was going to put in & i saw he had no comdom so i said NO! he might of has per cum on his penis & it touch my pussy still nothing happened today is aug 21,2014 & im 2 days late from having my period im so stress .. HELP ME