[Amorex]

I'm 18 years old(19 in a month), I had been taking Birth control(Ortho 7/7/7), I stopped taking it a month ago because I had been getting my periods 1-3 times a month. My period always starts on Sunday but this month it did not start until Wednesday and on Wednesday it was only a few drops of orange blood and then it stopped, but then on Thursday I started getting a pressure in my lower back and the cramping was bad enough that I did not want to move at all, I went to use the wash room and I had soaked through my pad, When I went pee, there was a lot of bright red blood clots in the toilet and the blood clots would not stop. From the time I got home from school, I went through 3 different pads, on one of the pads, there was a bigger thicker blood clot that had some shape to it. It's Friday morning and I still have a dull lower back ache and some pressure on my pelvic; I wasn't able to 'suck my stomach in' but now I am and my nipples had been sore but not any more. Does this sound like I might have had an early miscarriage?
I had not taken any pregnancy tests recently, the one I took 2 months ago was negative but the line was so faint I could barely see it so maybe I tested too early?