38.5 weeks growth ultrasound

So I had my nst test (I get them twice a week because I’m 36 and my OB said I should monitor more closely) yesterday. Baby girl is due Mother’s Day and is measuring 8-8.5 pounds (based on the ultrasound after my nst). My OB’s office called and said he wants me to come in cause he’s worried she’s getting too big and wants to discuss birth plan 😭

How accurate, in your experience, is growth measurement this late in the pregnancy? I didn’t have it done this late with my son who’s three. He ended up 4 days late and was 7lbs 8oz. vaginal birth.

I just really am nervous he might suggest inducing or that I might need a c-section.