I made a mistake and my period is late

There was a similar post about something like this but while I was on my last period my boyfriend and I were horny so I just let him stick it in there was no movement at all but I’ve heard pre cum can still get you pregnant but he swears that he took it out before then it was probably the second to last day on my period and I realized soon after that that wasn’t a good idea but idk what to do because now my period is 5 days late and I can’t tell anyone and I never really got a sex education and I’m honestly really scared to post this because some people on this app can be really critical but I need help