Asymmetric growth at 35 week ultrasound

Meg
My OB sent me for an anatomy scan since my fundal height was measuring behind.
I am 35 weeks. U/S showed head is measuring 37 weeks and stomach measuring 33 weeks. At my 20 week scan everything was measuring at 30 weeks.
They checked blood flow of cord and looks good (guess if flow is bad body will prioritize around making sure baby's brain gets what she needs)
My OB just called and said she doesn't know what to make of it and is having me come in for NST. What do you do when OB doesn't even know what to say?