my boyfriend and i had a unplanned night where we had sex, he went to pull out before he came, but does not know if he came in me at all he thinks that he might have a little, i had just got off of my period like two days before this happened. i went and got the plan B and took it about 15 hours after the incident. 7 days later i started bleeding lightly and it lasted for 3 days is this normal??