I accepted a job offer but now I’m confused

i’ve been working at the same place since i was fifteen, so this is pretty much new to me. i got a job offer from a decent company, accepted it, all that. did the interview, direct deposit stuff, I-9, all that. they said they’d contact me back after my background check and stuff goes through, which apparently it did but i haven’t heard back yet. is this normal? if it’s not what’s a normal amount of time to hear back??