Aside from pregnancies with known risk factors, a LOT of women who are expected to have normal pregnancies and births are just plain talked out of trusting themselves and inculcated into this culture of "I'm pregnant, these are all the scans I have to have cos that's what you do" without questioning lots of things - the validity of the results, the variability of interpretation, the unproven safety of so many US during pg, then the skill of knowing what to do with results and how helpful they are to wellbeing during pregnancy anyway!
When I saw GP's during pg (when I had a bad cold or non-pg need) it was generally very confronting for them a) that I had no US information to give them and b) that I was planning a homebirth. They tried so hard (EVERY TIME!) to cast doubt on my instincts and to insist they knew what was happening with me more than I did.
For my first pg I went for 2 US with the same person and she was lovely - none of this 'great, you've come to seek the services of a higher power than yourself' crap.