I agree with regards to baby knowing best & wondering how it is a scan can be more accurate then an actual date - it doesn't make a great deal of sense to me.

I have great respect for my Ob. & he has been very respectful of my wishes and I understand his view is a medical one & I guess that is why we engaged with him in the first place. I do my research, discuss with my DH, we make a decision & have a fall-back if we think we need one & then we discuss with the Ob. Sometimes I think I am the most opinionated & strong minded patient he has (since my appt's take between 15-30 mins and just about everyone else takes about 5 mins...although they might not be first time Mums so they may not need to discss so much). He is always willing to give me the time I need and explains the benefits & risks from his persepective but allows us to make the decision.