I’ve been using these - they’ve got really good absorbency but are not bulky like standard maternity pads - https://www.boots.com/boots-ultra-slim-maternity-towels-12s-10291542
I use reusable period pants. Made me feel so much better compared to the pads.
Maybe try adult nappies basically I was having to use these
If regular pads aren't enough I would recommend still using maternity pads for a while longer, I stopped using them with my first baby as I thought I wasn't bleeding enough for them but you'd be surprised how much they absorb so it might not look a lot but will be much more than you think. Then as I bled less I used period pants as I much prefer them to sanitary towels xx