Closed August 19th, Mortgage Resold Twice Already

Hello, from what I'm seeing on the rest of the internet, this is common, but I don't even make my first mortgage payment until October 1st, and my account has already been sold to two different servicers. It feels weird and scammy, and makes me nervous to want to create accounts with these people. How do I know what's real and what isn't? Is it normal for it to be sold before you've even made one payment?