worried after taking plan b?

hey so after a seemingly wonderful valentine's day date with my boyfriend, out of all things to happen to me, the condom broke!! panicking, my boyfriend reassured my worries with buying take action, one of the cheaper alternative brands to plan b. taking it not even two hours after the incident, i feel like i should be okay. BUT i'm still just so nervous?? is there any possible way of the pill failing? i'm 19 i really don't want a baby idk if i wrote this just to be reassured by someone or what but yeah i'm just so scared what if this emergency contraceptive pill doesnt work?? anyone w experience, can you help me out? did it work for you guys? thank you!