Growth ultrasound 5lbs 13oz baby already 😳

Had a ultrasound done since I was measuring ahead I’m 34 weeks & 4 days. Baby is 2 weeks ahead weighting in at 5lbs 13oz. I’m trying for a vbac this pregnancy was wondering if any other moms babies was that big at 34 weeks & 4 days and what their birth weight was ? My doctor seems to think if go full term I’m going to have a big baby. Also my baby is already head down and has been for about 2 weeks. When did you go into labor once baby was head down?