Oh, Cynthia, I wish I had answers for you. What you are going through is just so very unfair.
I was wondering about progesterone, but you had that covered this time. You said you are doing genetic testing--does this mean on the baby you just lost? If so, that might give you some answers. Have you had this done any of the other times? I would think that if they all had chromosomal issues, that would point you in a very different direction than if they tested normal. I hope you get clear results that are informative.
I wonder about the Rhogham. My midwife is very opposed to it. She is something of a maverick and very few people would agree with her, but she really does not like that protocol and does not think it is necessary. She says that in a birth that is handled properly, the blood should never mix. But I'm not sure whether there are any options there when you have already had multiple pregnancies and have had Rhogham in the past. I can try to get more information from her if you are interested.
I would not think DTD could be related. If you miscarried because your cervix was weak, perhaps that could be a factor, but that doesn't sound like that has been an issue.
Did either of your REs ever have any answers as to why things went so wrong with your cycles when your pretesting was all good? It seems like they should be able to figure out what is going on.
I'll throw one other thing out there, although I have no reason to think this is relevant to you. I have celiac disease (gluten intolerance), and I know that this can be a cause of infertility and miscarriages when it has not been diagnosed. I have been gluten free since I was two years old, so this was not an issue for me at all, but I know that some people discover they have celiac as a result of having fertility struggles and multiple miscarriages. It might be worth doing some research just to see if you have any sign of a gluten intolerance (or perhaps there are other food intolerances that could do this too).
My last thought is that perhaps a naturopath could help you. I have seen one on and off for the last few years. He uses muscle testing and treats with nutritional supplements and diet changes. I'm always a bit skeptical, but I get good results. I went back this fall because I was having horrible allergies for the first time in my life, and now they are gone. I went in a few days ago with horrible swollen lymph nodes and the worst headache I've ever had, and he gave me some supplements that got rid of it within a few hours. I know they have also helped women with fertility and pregnancy loss issues.
I hope you get some answers soon. I think of you many times every day, and I am praying for you.