I bled for 6 weeks, and for me...it actually only got a tiny, tiny bit lighter
Of course for the first couple of days it's really heavy, but after that it was still like a heavy period for me.
I wore maternity pads probably for over half of that time, just because I was more comfortable doing that (I was super paranoid about leaks etc)...and then toward the end, just as I got more comfortable really - the overnight ones. All by Libra, they were great
It didn't properly get lighter for me until about two days before it stopped completely...then came back heavy for a day, a day after it had stopped...then it was finally gone. And I haven't had a period since! (DS1 is 18 months and still breastfed, DS2 is 22 weeks gestation)
My advice is just be prepared for anything.