plan b??

okay, me and my boyfriend had sex with a condom friday night, but when we got done he just looked at me, he showed me and there was a little rip in the side. it was only in the inside not on the outside. he said that it happened when he took it off but i was worried so i took plan b sunday. and i'm so terrified. what are my chances of getting pregnant. also my period doesn't come till the end of the month. helppp