Applied at ampm for Unknown

I recently applied for a job at ampm and had an interview last Friday. Since today is Monday, I'm starting to feel anxious because I haven't heard back yet. This is my second job application; my first job hired me right after the interview, so this waiting game is new to me. I know they do background checks, which can take a few days, but I'm worried that if they decide not to hire me, they won't inform me. Am I overreacting? Should I wait a week before reaching out to them?