My biggest "what if"

Lately, I've been thinking a lot. This can be dangerous, because it usually means I'm making important decisions, second guessing important decisions, or am dwelling in the past. Today, it was me realizing that had I not miscarried in November, I'd be 24 weeks/6 months along already...and I know I can't live by what-ifs and all that, but it's hard not to wonder what things would be like right now if I still were pregnant. My "what if" thoughts about that often spiral into other "what ifs" related to money, and the house, and our family, etc. until I end up consumed with them. So I guess I'm wondering what the rest of you do when you're so consumed with what things could have or will be like...am I just going crazy or do other people wonder about all these things too? I wish I could just turn off my brain sometimes....