bruise from pump?

laura.noel

OK, frequent pumpers, can you tell me what I'm doing wrong? 

My pump (Medela Swing) leaves a bruise on the edge of my nipple on one side. I have 24mm and 27mm shields. I don't get any milk with the 24mm, and with the 27 I get the bruise. It only does it on the right breast.  My right is smaller than the left, but the nipples appear to be close to the same size, and the 27 works great on the other side. The bruise is right where the shield comes in contact with my breast, which also happens to be really close to where LO latches with his top lip,  so it really hurts to nurse for a day or so after every time I pump. 

I don't pump a lot (not going back to work for 4 more months)  but I'd like to start putting aside a little stash, so I'd like to figure this out.