Ask your doctor about starting progesterone pills/shots/suppositories when you get a positive test next time. I had an SCH with my DS, was put on Progestin pills 2x a day, and it cleared on its own. I never had bleeding, just ALOT of painful cramps. My best friend was never able to stay pregnant either until she started on them and managed to stay through. It might not be enough for you, or even the right treatment, but it's worth bringing up.
I just went to go and see my doc for a follow up appointment and he said that exact same thing! He told me that when we get pregnant again he is automatically putting me on progesterone supplements and baby asprin no testing needed.. Im already starting myself on the baby asprin and prenatals i figure ill get ahead of the game. Your story gives me faith that one day i will be holding my little one instead of saying good bye. Now its just recovery time and some R&R!