I do both. I was exclusively pumping for a while but recently got my son to latch again. A lot of people don't like pumping because they don't have the correct flange size. The size that comes with the pump is a 24mm or medium. I had to reduce down to an extra small. If you're not using the correct size it can hurt like hell and you won't get the most output. It's good to pump some so if you ever need to be away from your babe you won't have to use formula.