Due date changing from 9/4 to 8/31?

So this whole pregnancy my due date has been September 4th... well I went to the doctor yesterday for regular check up and my doctor vaguely mentioned something about my due date being in August?

I didn’t think anything of it at the time bc she was giving me lots of information and my pregnancy brain was just trying to follow what she was telling me 🤣 lol but I just noticed on my appointment summary she put my due date as August 31 now?

So does that mean it’s changed to earlier now ? Do I need to update all my baby apps to be due 5 days sooner lol 😳