When a baby is first born and then they eventually run tests on them what exactly are they doing just drawing blood?

I don’t want my baby out of my sight at all so that’s why I’m asking this.

I’m anon because idk if this is a dumb question or not🥴🥴

Canton Ohio is where I’m from. Everyone always says they HAVE to take the babies out the room for testing but I don’t want her anywhere I can’t be.