my ex-boyfriend and i had sex for the first time a week ago. it was his second time to have sex and it was my first time. he went into me about halfway for less than a minute but then pulled out cause it hurt alot. it was not long enough for him to ejaculate but im worried that pre-sperm may have come out. i was due for my period two days ago and it still hasnt come. altho this isnt any differnt from any other time i have had my period cause im still irregular considering i am only 15. i am still very scared that i could become pregnant and i dont know what to do.