am i just being paranoid

i had sex on monday, the condom broke and i took a plan b right after. i was 28 days in my cycle already but now i’m 3 days late. i’ve been getting cramps, my nipples were hurting a week before i took the plan b. am i just being paranoid?? it was the first time i’ve taken a plan b so i don’t know. i forgot to mention that he did cum in me because it broke. on the app, it said there was a 3% chance of getting pregnant