Mine says the same: that they are doing my background check. However, for what I know you shouldn't make too much out of it, nothing gets started until you pass your medicals.What is the status of your application? Mine is also a similar timeline, and it says background verification in progress for me. I thought that started only after passing the medical. So, I'm just curious.
The most they will do at the moment is to check if your application is complete, that is if you submitted all the paperwork.