I can't answer your question but just wanted to drop by & offer some encouragement. I too had 3 m/c's before my successful birth. I'd had a lot of testing done over the years because of infertility & nothing was ever found to be wrong. I was never given a reason for my losses as they were all early ones. For me it was a case of 4th time lucky without any medical assistance. I hope it's 4th time lucky for you too.