opinions needed please

i made the poor decision to have unprotected sex dec. 20th with my partner. i got my period the day afterwards & it was heavy which is a normal cycle for me. i was supposed to get my period again around jan 23-ish & it hasn’t come at all. i haven’t had sex since that day in december. i’m about 20 days late currently. i’m terrified to the core & i don’t know what to do at this point. do i take a test? i doubt i could be pregnant but i get so paranoid easily & will stress over it so badly.