As often as baby would eat you should pump. If you're exclusively pumping, pump every 2-3 hours. If you're also breastfeeding, pump after every feed. Don't wait until you're "hard" to pump.

@kparis, I want to bf atleast a year & I also need to save up so when she's with the sitter . Should I wait until my boobs get hard to pump or ? I've only done it once

I do at lest 3 times a day, sometimes 5 once when I wake up, once mid day and right before bed but that's because I'm stocking up for when I go back to work full time, and I have a goal to bf for 12-24 months, it really depends what your trying to do, and why your pumping! I also produce a lot so if I don't pump it hurts.

I do mine at night since my son sleeps for a few hours. and once I get off work cause I can't pump during the day. and whenever my boob feels full, or one does, I see if jr is up, or sleeping and or hungry. then I decide to do it or not.

when you get the chance and you have a good boob to drain at least 3 ounces.