I would talk to a doctor as soon as possible. You can't afford to lose a lot of blood, not after major surgery and not while nursing your child - those take too much out of you as it is. I had a C-section with my first and at three months had my OB insert an IUD (because I knew I wouldn't be consistent with the pill). Shortly thereafter I started hemorrhaging, mildly at first, then heavier over the course of a month until I was bleeding heavily all day. This culminated in a week-long migraine. My OB felt it was just my first post-partum period and that we should leave the IUD in, but I felt convinced it was the fault of the IUD and insisted on having it removed. Within a day or two, I'd stopped bleeding, and the migraine went away. (Don't get the wrong idea - my OB is a very good doctor and I'd recommend him to anyone; he was just mistaken in this instance.] Anyway - lots of bleeding is a bad thing, and you need to do what you can to find out what's causing it and to make it stop.
Congratulations on your new baby, and please accept my family's thanks for the sacrifices you and your husband are making for our safety. :)