Quoting Asher and Haddie's Mommy:" We're working on the latching, she's got jaundice and while my milk wasn't coming in, we had to supplement ... [snip!] ... has stopped latching properly. How long should I be pumping per session? I feel like I could pump all night at this point. Lol."You want to empty the breast as much as you can and pump for about 5 minutes after that to tell your body to make more milk.