Possibly a Dumb Question about Beginning Pregnancy Timeline

I’ve wondered this for a while, but my Google searches have come up empty.

Assuming you have sex that leads to pregnancy, and that sex happened right before your period would you miss the period that comes right after. Or would you have one period and then miss all those that come after (for the duration of your pregnancy?)

I’ve always assumed you miss the one directly after, but I’m just curious about the timeline of when your body officially “becomes pregnant” and starts behaving as such.

Sorry if the question is dumb but I never had any type of sex ed and grew up in a family that did NOT talk about anything related to reproduction. I just want to be informed and like I said, Google only took me so far.