They have tested you for celiaki right? You've had so many tests and so much going on so I guess they must have ruled that out too. Just happened to find a text today saying that women with celiaki who aren't following a gluten (that's the Swedish word, can't find the English word right now, but it's the wheat protein ) free diet have a 9 times higher risk for miscarriage than other women.
It's probably something else you have, otherwise I'm sure they would have figured it out by now.