Our baby is at 36 weeks. the recent ultrasound showed growth from 35% to 37%. there may also be increased blood flow to the brain. should we worry?

Ok: An average baby will be measured at 50% in growth. Your baby's size is a little below average, but entirely normal. Interestingly, these measurements have nothing to do with the adult size/heighth of your child. I've never seen a report of increased blood flow to the brain, so i'm not sure of the significance of that...Probably good if anything.