im back...again

so i recently posted that i had sex & that the condom somehow had a hole in it, but we didn't know that until until he had finished in me (ew that sounds so weird) but anyway..i went to get plan b right away, like within 30 minutes of the incident ... my period is now 4 days late & im becoming more scared that i'm pregnant. both of our guts are telling us that i'm not, but why is my period so late then? usually it's late by a day or two, not fucking 4!!! i know plan b can make your period late, but is this too late?