About 6 weeks with both of mine. Freaked me out the first time, because I kept reading that it's only supposed to last a week or so, then turn pink and finally go away (after a couple weeks!). Then I do more research and talk to more women, and it seems that 4-6 weeks is about average.
Just be cautious of a big change in the bleeding. It could be a sign that something is wrong. And watch that it doesn't have a foul odor (other than bloody odor), which could be a sign of infection.
It also might stop for a day or two, only to come back for another week. I did that a few times with this one. I kept thinking it was over, only to have it come back again.