I had DD after two MCs... had another after her but currently 5w and hoping this one sticks!
My OB said that a lot of pregnancies end in MC, many more than people realize because so many are before they ever get a BFP but even of the ones that people know about, 20-25% can end in MC. She said that most of the time it doesn't mean anything is wrong with the mother, it's just that the process of forming a baby requires so many things to work out JUST RIGHT that sometimes things just don't line up and your body realizes it. She said each time is like a roll of the dice.
That helped me feel a bit better, knowing that 1. It's so common so at least I'm not the only one and 2. That just because it happened before doesn't mean it's going to happen again.
My mom had an MC before she carried my brother and I to term, too... sometimes I think of it almost as a body's way of doing a "dry run."
Positive thoughts to everyone!