I've been pumping 3x/day since returning to work 2 months ago. In the past week or so, every time I turn the pump on, there is a lot of discomfort. The pain gets slightly better as I pump but it's always uncomfortable. It wasn't like this before. I already sized my breast shields up twice and it doesn't matter how high I have the suction. I'm really not sure what's wrong. My output has decreased as well. Any ideas?

ETA: I have a Medela PISA