I'm sorry if you're experiencing one! They can last awhile... you can bleed for some time before actually passing any pregnancy tissue, and then it can take a few weeks for hcg levels to fall back to zero, depending on how high they were to start with.
(Details follow- don't read if they will upset you!) I had a m/c with my first pregnancy- it was first diagnosed around 9.5 weeks via u/s (no h/b and the baby did not measure correct for dat es.) I didn't start bleeding for another several days, then I had some pretty painful cramping on and off for about twelve hours, after which I finally passed the tissue that had been left. Then I had another day or two of heavy bleeding and then spotting... it also took my hcg levels about a month to return to zero, but they were pretty high for a m/c (around 9000 or so.) HTH a bit... sorry you are experiencing this!
at 5:25 PM on Nov. 1, 2010