How much blood is normal?

I had my cervix checked today. It's the third time. The first time I had a little spotting. The second time nothing. Today is different. It didn't hurt at all but by the time I got to my car I felt gushing like I started my period. I thought it was just the lubricant coming out. When I got home I found that my underwear were bloody and so were my legs. I did pass a small clot into the toilet. That was 30 minutes ago. I put on a pad and I'm waiting to see how much comes out to see if I need to call my provider. I am having some cramping and pinching and baby is moving around still.

My question to all of you is... How much is too much blood.