Baby weight and Baby Hair

Hi all!!
Random question, and this probably only applies to you that have had a baby already, but has anyone had them predict the weight and it was off? Or think the baby had hair and it didn't? The weight of our little one has fluctuated so much it's crazy!!! And I was bald, but it looks like our tiny man has some hair on the ultrasound!!! My husband had some, but that's just crazy to me that they can see that sort of thing!! Just wondered if anyone else had doubts!!! 😁