Help / advice needed!

I had a D&C; on 7/31 and afterwards my Doctor did thyroid testing and turns out I have subclinical hypothyroidism. I've been on medicine which has helped and gotten me stable but now I recently got a BFP this month. I'm 3 weeks (still early) and talked to my OB and she is just going to run HCG today and Wednesday, then not ever again as long as levels check out. She said they will only check thyroid every trimester. I've read it should be every 2 weeks. Also, she isn't going to heck progesterone and won't do early scan (maybe one at 6 weeks). Thinking I need to switch OBs. I don't feel like I'm being heard. I'm so afraid of losing this pregnancy and want to make sure everything is ok.