So sorry you are going through this. I had three later mc and an number (sounds awful, I lost count) of much earlier ones at under 6 weeks. Some got tested, and had unusual chromosome defects.
I was in my 40's so perhaps that's not so surprising but I was getting pregnant every second or third month, so clearly fertile.
I saw the "top" consultant in my area and he had a number of suggestions for me - go onto vit D3 supplements and 5mg folic acid (that's a very large dose), as you get older, or if you have certain conditions (autoimmune I think), your body can't metabolise folic acid or vit D as well, and both are needed for proper separation or chromosomes in the embryo directly after fertilisation, and also I was to take a mini aspirin daily from tiger day I got a positive preg test.
He said this was his routine advice to all his older ttc women, and that although he could test for certain blood factors, he felt it pointless as there are so many they can't test for. These supplements/medications are all anti inflammatory, and IMHO, work because many women have undiagnosed autoimmune conditions which develop as we get older.
My next preg was successful and is now 3years old. Subsequently I developed(or rather they got worse), several conditions with a strong autoimmune component including thyroid and joint problems. When I removed (all) grains from my diet (I follow a Paleo diet which is great for people with autoimmune issues).
Anyway, joining together the two halves of my experience, I'm going to suggest discussing the supplements and aspirin with your GP or consultant, but also dietary change... It can do absolutely no harm to go grain free (especially wheat and gluten free), and it may do some good. The Paleo/primal diet places huge emphasis on fresh, unprocessed foods with no chemical additives, and it is very low in inflammatory foods. For info, Marks Daily Apple blog is a great starting point. It has a searchable archive so you can find all the articles related to fertility, ttc easily. Wheatbelly blog is also interesting reading.
Good luck
!