w/ my first, i was way too active and up and about too early (not by choice, but it was horrible), so bled more heavily for the entire 6 weeks. it was bad. i learned my lesson.
i'd say i bleed steadily (though not heavily) for the first 2-3 weeks postpartum. and it gets worse if i've over done it during a day. but the really messy horrible stuff eases up in 4-5 days for me. i used disposables and trifold diapers for that the last 2 times.
actually, i have a huge stash of trifold newborn size that are perfect, and i should hunt them down. i'm a diva cup fan myself, so haven't used anything external since my last birth... but i loved the convenience and effectiveness of the trifolds for much of the bleeding. I just keep a stash next to the bed w/ a pail and larger trifolds and cotton clothes for the rest of the messes. I do a lot of laundry due to night sweats, bleeding, babies exploding, spitting up, and milk oozing everywhere those first few weeks anyway. i wish i could send trifolds to everyone!!! i probably have enough.
generally, week 3-4 i'm trying to figure out if ALL the bleeding's done (and my husband is asking consistently) while it's kinda a day by day thing. usually by the start of week five i'm totally healed up.