Due date August 31 but schedule c section August 24 who else has my due date and having a c section

So my original due date is August 31 and they changed it to August 26 but for some reason they are going with the 31. I have a schedule c section Aug 24 I keep trying to tell my dr that I'm not going to make it to 40 weeks it may be more 36 or 37 smh who else has this issue