Late period or really early miscarriage?

A few days before my period was supposed to start, I started to spot. It was brown with a little pink and it only lasted three days and was gone. Then, 9 days after my period was supposed to start, I got what I think was my period but it was a different color than usual and it was so slimy with little clots that I had never gotten before.

I feel like I was pregnant and just miscarried really early because I had the symptoms of pregnancy. I felt so nauseous in the morning and had terrible headaches and when I had spotted those few days before my period was supposed to start, I had the worst lower back pain that I had never felt before. Anyway, after I started bleeding 9 days (after I was supposed to start my period) my headaches and nausea went away and I feel fine now. Could it just have been a late period?