my girlfriend usually has her period on a tuesday. she is on birth control and we had sex on monday, however she accidentally took a white pill rather then a green pill. just in case, she took a morning after pill. seeing that she took it so close to when she was supposed to get her period, and that she messed up with the pill to take, how messed up is her menstruation cycle going to be? when can she expect to get her period. she is already 5 days late, she took a pregnancy test and it was negative.