I also wondered if it might not have something to do with using a specialist? If you've seen a FS and you don't want to be left hanging with no one paying any attention to this hard-won pg, the idea of waiting weeks and weeks to see someone might lead many down the path of an ob? Also seeing the one person probably appeals, given that there have been so many specialists and drs involved and I imagine not all of them good!
This was the case for me