Have you had your Thyroid Stimulating Hormone tested?? because I was the same as you, I had 3 pregnancies in 4 months one after the other and at 5 & 6 & 5 weeks they all left me, I spotted early then started bleeding with HCG levels very low. After the third miscarriage I thought thats it I'm getting every test under the sun done! I need to know why this is happening. Well low and behold my TSH was out of the normal ranges and the endocrinologist Dr Gavin Sacks told me it was because this level was high that I was losing the babies. I've been on Oraxcin since diagnosed in Dec 08 because Im hypothyroid which means its slow and I put on weight easily. I've had 2 blood tests and am now in the normal ranges and can try to fall pregnant again. The Dr said that I have 60 to 70% chance of a successful pregnancy if the levels are in the normal ranges and taking into consideration my age and my weight oh yes and my husbands age.

So I found a lot of these tests on this website its under the thread tests for recurrent miscarriages. Goodluck and I hope you find some answers.