Amanda I m so sorry you're going through this. Of course I hope it isn't a miscarriage but even all the stress that spotting causes is horrible. I hope it's a sticky baby and stays put.
I've had two miscarriages and one of them was an early one and happened naturally with no D&C. I started spotting on a Saturday afternoon but within a few hours I was wearing a pad and by Sunday I was full on bleeding and passing tissue and by the time I got an u/s on the Monday it was over.
I think you have a great chance that this is random pregnancy spotting. I've even heard of women having full on bleeding and keeping their babies.
With my second miscarriage I had full on bleeding but the sac stayed put even after I thought it was over and even after I used cytotec to get it out. Actually with my second miscarriage the bleeding wasn't even related to what was going on with the baby - it was because of a subchrionic hematoma, a pooling and clotting of blood by the placenta. And I have known other women on here that had full on bleeding and no miscarriage.. so have some hope and I hope tomorrow you find out it's just harmless spotting.