How much time will it take to get my period after having the morning after pill?

Hard to predict.: Potential Side effects w emergency contraception include menstrual flow changes (spotting, bleeding, early or late period). Take pregnancy test & notify Dr if your period is 7 or > days late. Even though Plan B is out of your system relatively quickly, the hormonal changes that occur may take up to several months after the Plan B was taken to even out.