41 week EDD?

Sawyerplus1

I've been meaning to ask this for a while. An acquaintance of mine is due right away with her first LO. She had an original due date, but then it was moved to 8 days later (based on an u/s I think). She is approaching this 2nd EDD but in her mind she's already 40 weeks pregnant, and that her EDD is actually set at 41 weeks gestation. In other words, when they moved her EDD, she didn't also adjust how far along she was at the time.

Is it possible that her Dr is encouraging this view point? Or is my friend just mistaken? I haven't corrected her, but whenever I tease her about going late she responds with "i hope not considering i'll already by 41 weeks on my due date" or something like that. I'm also not a fan of unnecessary induction, and am worried that she'll rush into an induction b/c she thinks she's already 'overdue' by her EDD. 

Has anyone heard of a 41 week EDD? Or is she just mistaken about how far along she is?