Help please! Took option 2 pills (plan b)

Hi all
I had sex for the first time on the seventh day of my cycle and we used a condom but I'm not sure if Precum touched the outside and also he checked the condom after and there was no leakage! I took option 2 after 7-8 hours and I'm still scared about how effective it is has anyone been in this possition because I have to wait for at least three weeks for my next period ! I'm not on any birth control pills and I'm extremely scared please help me