What Does Bright Red Bleeding 6 Weeks After Postpartum Indicate?

I am six weeks postpartum. My postpartum bleeding has been stopping/starting irregularly. It consisted of bright red for about the first three weeks and then tapered off to the brownish/red and finally yellowish to clear. Now on my sixth week I've returned to bleeding bright red. No fever/chills. I am breastfeeding. I am concerned that something could be wrong.