I think that I used to be quite lucky - 5 days of fairly mid level flow. No cramping, slight backache. Then I went on the pill and, along with what I had been experiencing, got pretty bad cramps for the first day as well. Tried several different kinds of pill, and it was the same with all of them. Still, it wasn’t bad enough for me to stop using the pill.
When I finally came off the pill about 8 years later, my period returned immediately, but had decreased to 1-2 days of light flow (some days it was maybe 2 regular tampons worth, and a pad overnight) and no cramping again.
I was worried that this indicated that there was some problem with how things were working, given the change, but several gynaecologists didn’t seem to think it was anything to worry about, so I eventually just decided that I should just be very, very grateful.