Due date

Quite annoyed, my due date has been changed to August 18 instead of August 5. Due to the 5th was going off of my LMP and they are going off of my first scan at 20 weeks (doctor never sent me for an early scan) which showed August 18th. Sticking with the LMP would show the baby growing 2 weeks behind but now it shows “normal” just annoyed because trying to plan with family coming into town and plan a baby shower. Now if my doctor agrees with the radiologist tomorrow then just throws all my plans out the window