Am I having a miscarriage?

Since Sunday, I have had awful stomach pain. I started my period on Thursday and I have now had it for 9 days. I was constipated for a good amount of time (not sure if this is relevant) and my stomach constantly hurts AWFULLY for like 10 seconds at a time and then it goes away and comes back. The weird thing is, my period also came a week before this 'period' started. The blood that is coming out is very dark yet light in volume. It smelled AWFUL. I didnt notice any large clumps. My stomach still hurts, and Im not sure if it is from a miscarriage or if it has to do with my constipation issues. The constipation ended today but the stomach pain still persists.