Connection between PCOS and thyroid hormone?

Hi,
I've had PCOS since I was a teenager. When I was 30 my husband and I decided to have children. It was a challange for me because I had periods once in 3-4 months. I had no idea when I ovulated. Then I read the book "TAKING CHARGE OF YOUR FERTILITY" (I HIGHLY RECOMMEND this book especially to women with PCOS) and thanks to the info in the book I got pregnant the very next time I ovulated! Apparently, during ovulation women have an increased vaginal discharge (similar to mucus from the nose when sick). That was the clue I needed to get pregnant. However I had a spontaneous miscarriage after 5 weeks--probably due to my PCOS.

A couple of months after my miscarriage I started taking Synthroid (thyroid hormone). I am not hypothyroid. The only reason I took the thyroid hormone was that my thyroid gland was enlarged.
****TO MY SURPRISE, I STARTED HAVING REGULAR PERIODS while on Synthroid!!! I'd never had regular periods before that!****

After 3 months I was ready to get preganant again. I got preganant immediately. This time my preganancy was successful. I had a baby boy in June 2001 at full term.
I still wonder whether the thyroid hormone was the reason I had a successful preganacy.

I stopped Synthroid(thyroid hormone) after giving birth to my son.

I've been trying to get pregnant for 5 months now, and I'm failing to get preganant even though I know for sure when I'm ovulating. I suspect PCOS has something to do with it. But I'm also considering going on Thyroid hormone again to see whether this will help.

All my lab work has always been normal--normal insulin, blood sugar, testosterone, estrogen, TSH, thyroid hormones. However, I've always had polycistic ovaries, increased facial hair and irregular periods. I also have a goiter (enlarged thyroid gland). But I've never been overweight.

Does anyone know of any connection between PCOS and thyroid hormone?

Thanks,
Zora