Should I keep pumping even when it’s very painful?

I’m 6 weeks postpartum and I’ve been pumping consistently since day one. The LC in the hospital sized me at a 21, but mentioned a 19 might be better but she didn’t have any to give me. I’ve been using the 21’s with mostly success, a little uncomfortable but not unbearable. A few days ago I ordered some 19’s to try out and they did seem better at first. But as of today it’s very painful to pump. I’m trying to isolate what exactly it is that’s hurting and I’m pretty sure it’s my areola on both breasts, but one more so than the other. I’m unsure if it’s related the the flange change, or just coincidental timing, but I’ve switched back to the 21 and it’s still very painful where I am grimacing the whole pump.

I am going to try to get in to see an LC, but in the meantime should I keep pumping through the pain? I’m worried I’m doing more harm than good with how much pain I’m feeling, but I also don’t want my supply to drop. If/when I do keep pumping, I’m not sure if I should go with the 19 or 21 in the meantime as they are both so painful now that my areolas are so inflamed. For reference I’m between 15 and 17 on the pumpables sizing printout right after pumping. I’ll measure again when they settle down.