I'm struggling to figure out what size. I think judging by what my actual nipple is measuring at that I should be using a 21mm or lower. However, the lactation nurse I saw said I should be next size up from what I'm using, which is 24mm, came the pump. Kind of seemed like she was judging it based not just off the nipple but my areola too.. I'd like to atleast make sure I'm going in the right direction when I buy more.

My milk is coming in and feels like I can't get my breast drained. Definitely getting uncomfortable. And the boob is feeling a bit uncomfortable when I pump.

Any ideas?