i've had sex many times before with my boyfriend but last time we had it (the 9th of this month, to be exact) he slipped into me accidentally... we weren't using a condom. he withdrew almost immediately, and he's quite sure he didn't ejaculate or anything but my period was due the next day and i didn't get it... and i've taken three tests since and they've all showed negative... but i still haven't got my period and i think paranoia is causing me to feel like i'm gonna throw up... nothing else is wrong except that i still haven't got my period... i've had these irregular spells before but that was when i was still a virgin... is there a chance i might be pregnant???? help!!