Is it normal that my pump slightly hurts during the letdown phase but not during the actual pumping phase? I have an older model medela Pisa. Could ot be because this is the first time I'm pumping in awhile? I've tried so many flange sizes. I should fit a 21 mm. I've tried 27,24,33,etc. Someone mentioned to me these stoppers that can go in flanges for people who have elasticy tissue. Does anyone know the name of those inserts? I just want pumping to be painless.

It's literally just during the letdown phase. The nipples are not tender or in pain afterwards.