Hey hun,
Just thought I would pop in and say good luck. I too was told that DS was going to be big, he was always measuring about 2 weeks ahead. He was born at 37 weeks weighing 3585 grams (7pd11ounces) so yeah, he was a big bub considering. But I am thankful for that because if he was too small, he would have been sicker having been born that little bit earlier (I was induced due to pe). Luckily my very wonderful OB (yes, private hospital OB with 50% natural birth rate) said "bah, you just don't know what size baby you can push out until you are pushing! so let's not get too stressed). She even advised against the sizing scan as she didn't think it added any useful information.

I felt better in that situation, so I understand how annoyed you must feel hearing the opposite. However, the scan would have just given you some size info to take into consideration, but in the end, the choice is yours hun.

Good luck!