What Causes Unusual Vaginal Discharge With Bleeding, Clotting And Cramping?

I had some vaginal discharge an there was a long sting like thing come out when i wiped an there was what looked like a lil red ball an veins going through it. I think I possibly have been pregnant but 3 days later after passing that I started bleeding profusily an clotting horriblyand having severe cramping and lower back pain.I've never bled like that in my life. Did I have a miscarriage?