cant stop spotting

I have been spotting for like 3 weeks now. I have already had a period this month and since then my spotting hasn't stopped. I just had an ultra sound to check my ovaries and I do have small cysts on them but the Dr said she thinks I'm "pre-pcos" bc I still get my period. I'm supposed to start Clomid on my next cycle but I am worried I'll mis calculate my period. I am cramping but not very strongly like I do with my period. My blood is very dark and clotty. I don't know what to do..