What does this mean and should I be worried?

I just had my period on the 29th of September 2011 thru October 5th 2011 and I started having some spotting with clots (sometimes alot sometimes very little) on the 20th of October 2011 and I am still having it. It has been 8 days now. I don't know what this is. Should I be worried or not?
Symptoms: Nausea, Constipation, stomach aches, and of course the spotting with clots.

Worrying won't do anything to help at all. See a doctor.