Question please help

Jess
My Obgyn that I normally go to started doing a thing were he only goes to 12 weeks then transfers you to a different dr because he no longer delivers. Anyways he did my first scan at 6 weeks then I had another at 12 weeks. He told me my due date was 10/19 accorind to ultrasound and my LMP well I went to my new doctor and they said since he said that was my due date and my lmp matched we'd go with it. The only other scan they done was at 20 weeks and they literally didn't tel me anything not a due date nothing. Well i moved so  I am now seeing a new dr. My old dr refused to send my medical records so my new dr had to redo everything. After my appt with him he sent me for an ultrasound since he didn't have any previous ones except from 6 and 12 weeks. At the ultrasound I was told my due date would be 10/8 according to size of baby. I thought I was 31 weeks yesterday but according to it I was 33 weeks. I've not seen my dr since the sono so I'm not sure if it has changed. What do you ladies think. Baby right now is also weighing in at 4lb 4oz.