Currently bawling at the OB..

I was so excited for my appointment today. It was my last ultrasound and I haven’t seen her since the anatomy scan at 20 weeks. Well, needless to say, the ultrasound tech flew through the scan, literally measured the top of her head and her stomach, I didn’t get to see her or get one single picture. I was in and out in less than 3 minutes (no exaggeration). But what really upset me was my baby is only measuring 5 pounds 15 ounces at 36w3d and is due to be delivered in 2 weeks. My first baby was born at 40w2d and weighed 8.13 and she has always been in the 80-90th percentile and now I have this baby who is going to be born at 39w and is below average in the 44th percentile. I don’t understand, I have been SO HEALTHY this pregnancy, eating well and exercising. The tech says she’s measuring perfect, but it doesn’t sound perfect to me. Will it be wrong of me to ask to reschedule my surgery to AT LEAST 40w instead of letting them take her a week early being too small?