you can't get your period the first month of pregnancy... right?

this is gonna sound like a super dumb question, I swear I'm old enough to be having sex (I'm 21 lmao). I googled but found conflicting info?? at the end of May I hooked up with a guy and he thought that the condom MAYBE broke but I was on the last day of my period and he was just being paranoid. I got my period as scheduled the following month (mid june) and it was normal. I have an extremely short cycle (20-22 days) but I am now on my 24th day and have yet to get my period. I guess I was just kinda worried that I somehow still got my previous period yet am still pregnant? but that literally isn't possible... right? Like if I'm shedding my uterine lining I can't see how it'd be possible to maintain a pregnancy, lmao. I just wanted to make sure because I haven't been this late in months.