Let’s talk numbers 33weeks

Katyie • Due 9/20/2019 Bella Marie 💕

So at my sonogram today baby’s head was measuring in around 35 weeks one day but her belly was measured around 34 weeks 3 days and I’m supposed to be 33 weeks 5 days. Leg measurements were dot on for my 33 weeks. So does this mean she’s going to be a big baby? Will my due date remain? She’s head down and low “but not to low” whatever that means. Just don’t know if I should start packing our bags and putting up crib ect or wait until September like planned?