Baby bigger than 34 weeks and due date change

This may sound a little odd, but I had my 34 week prenatal appointment friday. While the doctor was examining me she says my daughter wasn't a small baby, so she asked if I wanted a sonogram to check her growth. When they examined her, she was measuring at 36 weeks, six pounds and in the 75 percintile. When I seen her I laughed because she is so chunky her thighs , head and fat fingers. The doctor changed my original due date from June 26 to June 18th. Have any of you ladies have this happen and was the baby really big. I'm just suprised how thus all came about. Now I have less time to get her nursery together and pack my hospital bag and hers.