40 week ultrasound?

FTM here. At my 39 week appointment the doctor had me schedule an induction date for 41 weeks (hoping it won’t be needed) and also told me to schedule an ultrasound for my 40 week appointment. The baby and I are both healthy and there haven’t been any issues the whole pregnancy, so I don’t understand the point in having a 40 week ultrasound. The doctor didn’t explain it at all. Has anyone else had a similar experience? Any explanations you can think of?