Wow, I'm floored by all this. It makes me reaaallly want my p4 tested throughout my pg. My RE seemed really quick to say "p4 is excellent. Stop it in 2 weeks." I wonder if I should have my OB test me...or maybe she'd be like your doc and not believe in it.
Sigh. I'm sorry you have conflicted opinions. I think I would try to put off the OB visit by a couple of days so you can talk to Check and get firm quotes from him to give to your OB. Goes w/out saying, I would stay on the p4.