is it possible you had the suction up really high without realizing it? that said, i know some women do need to change flange sizes after pumping for a few months. it might be worthwhile to try a different size if you are starting to have discomfort.
It of course had to happen today. The day after I signed the paperwork to donate 200oz of my frozen stash. Like I was already paranoid about needing it. Gheesh
Re: Flange size
this diagram does a good job showing how it's supposed to look: https://www.ameda.com/breast-pumping/getting-started/flange-fit