Im 15 And I Live In Minnesota, My Boyfriend And

Im 15 and I live in minnesota, my boyfriend and I just had sex about an hour ago. It fell out and when we were trying to put it back in we realized that the condom wasnt on him anymore and that he had ejaculated, after a while of "digging around" we got the condom out. After that we started look around for ways to reduce the risk of me getting pregnant. He's at walgreens getting plan B right now but if it doesnt work and I still get pregnant, how can I get out of a pregnancy without my parents knowing?