Me and my boyfriend were messing around yesterday morning in the shower and while he was fingering me I was jerking him off and he came on my thigh. I was pretty sure I didn't get any of it in me but I took plan b that evening just to make sure. Then we gott to messing around again and he was on top of me naked and he rubbed his penis head around my vagina and stuck the head in a little. I just got off of period at least three or four days ago. And I'm starting a new birth control tomorrow. I am currently not on any. Should I be worried if I took plan b and it will act as a birth control in the 72 hour window period? Please help!