Is it possible that I could be miscarrying?

My period ended June 25th. It was a normal 5-6 day heavy flowing period. Immediately after my period ended, I had crazy pregnancy symptoms so I took a hpt. Negative. The symptoms have continued getting worse so I took another test yesterday, negative. I also thought it could be ovulation since I'm due to ovulate right around now. Negative. 3 days ago I started getting this weird bloody discharge with what looks like small pieces of tissue and clots. I have very very very dull cramps but not crazy heavy bleeding or anything. Just spotting. This doesn't really sound like typical miscarriage symptoms to me but the discharge does resemble it. But I'm confused because I was always under the impression that a miscarriage happens all at once. Could I be starting to miscarry? Is it even possible for me to have been pregnant to miscarry?