Period vs Miscarriage

Dana
I'm curious on how to tell if my heavier flow this month was just a change in cycle or a possible miscarriage...? I read that a lot of women have miscarriages before they even find out that they are pregnant. I've been TTC for a while now and I thought this month would bring me luck but it didn't. (TMI coming up) 
This month my period was a lot heavier, I sometimes felt like it was coming out like a faucet and I had a lot of clots. It's since eased up but I still have small clots. 
I'm really trying to figure out if I'm getting pregnant and not carrying or if I'm just not getting pregnant.....