I'm sorry to hear about that.
If this just happened last night, and if you really are miscarrying, then it might have a bit before you pass any clots or whatnot.
I would have been 5 weeks pregnant on Monday, but Sunday I started bleeding a bit, I just thought it was spotting. But as the day went on, the bleeding got heavier and I started noticing clots.
If you were about 8 weeks along, I believe something can be seen on an ultrasound. If I were you, I'd be heading to my doctor's office ASAP to find out what's up!