Stressed

so i had sex for the first time last thursday, my fertility rate said 3% chance of getting pregnant. I’m not birth control but we did use a condom. The condom broke but we were both positive he didn’t cum. I wasnt going to risk it so i took plan b just in case because i was stressing out. My period is supposed to start tomorrow and i’m stressed i am going to be pregnant even though i’ve has plan b and he swears he didn’t ejaculate... any advice? thank you!