Hi clarebear,
If its brown or a burgandy colour its old blood and nothing to worry about. When you have a M/C you will definately know it. My M/C was very painful, I dont mean crampy but like a knife jabbing at me (sorry if TMI) and I bled heavily,like a heavier,clottier period(sorry again if TMI).If your not filling a pad and in no pain try to relax. I know ,I know easier said than done but honey you sound fine to me.If you have anymore concerns see your GP or go to the ER.
Another symptom of pregnancy : Paranoia