Due date help, please give me your input

Please help based on my last period my EDD was Dec 11, then they did and ultrasound early on they changed it to Dec 24. Then they did an ultra sound and changed my Due date to Dec 16. Mind you this has never ever happened to me. I’m pretty upset because I am already on maternity leave and those dates are a bit of a difference. As well I’ve been seen by all different doctors . Well when I saw this new doctor at my suppose to be 37w appointment he said we are going to stick with Dec 24..... that was my first time ever meeting him . So now I’m super confused and pissed off so I’m guessing I can give birth between the 11th and the 24th... idk why they kept switching doctors it was super annoying, I’ve been to this drs office with my previous pregnancies and none of this b.s happened!!! I am asking what you Guys think considering I want to put my car seat in the car just in case , but if i were to get into an accident it would be no good ..