Makenalelu, I would defintely see an RE. I think OB/GYN's only know so much and since you have thryoid issues too, an RE would be best. I also have been getting + OPK's very early (8-11 days) and I worried myself that my lining would not be thick enough. I talked with my RE and she and another RE there both felt that my lining was thick enough by 10 days. They said that since my periods are fairly light and only a few days (3 at most) long that the lining had enough time to thicken. I have had the lining measured 2 months in a row and it's been at least 8mm by 9-10 days which I think is the minimum. That may be the case with you too. Have they measured your lining at or around 10 days? This month my IUI's are being done on CD9 and 10. It sounds so early but my estradiol levels were showing mature follicles and lining was 11, so I'm hoping for a BFP this month.
I think the progesterone can be low when the cycles are short. My RE started me on micronized progesterone vaginal capsules last month after I ovulated. Maybe that would help you.
I've heard that clomid can make things worse. It can thin the lining more over time and if you have high FSH, chinese medicine says that clomid is a no-no. I've heard it can shut the ovaries down and it certainly makes your night sweats worse if you already have them. My RE gave me the option of trying Clomid but after learning more about it (I'm a big reasearcher), I decided to go staright to injectibles.
Danielle- I'm so happy to hear that you ovulated. That's some positive news that you needed to hear.
