I am now able to pump anywhere from 12 to 16 oz of breast milk at each pumping session. My son is 3weeks and we both have worked very hard on this. From the day he was born he was basically attached to my breast none stop once we got home I would pump after every feeding for 10-15 mins then after a few days I increased it to 15-20 mins even if I had no milk coming after 9mins I would still pump the full 20mins. Now I'm able to go long periods of time without pumping and still have no problem.