actually if you are exclusively pumping, is quite easy to manage your supply. if you want to increase the supply, you just need to pump more frequently. I did exclusive pumping for my first child and I managed my supply by either increasing or decreasing freq of pump. If you wish to have more supply, do not drop the midnight pump. I read that our hormones peak from 3am -5am. so if you pump once within this time, your yield will be alot. if you drop this pump, your suppy will drop. this is quite true for me. when i wanted to wean off, i drop midnight pump and my supply went downhill very fast.