Re: Output while at work
Most women need to pump every 2-3 hours for 15-20 minutes while at work to maintain supply. I was able to get away with pumping 2x at work when I had an oversupply, but needed to pump 3x once my supply evened out. You want to make sure your parts are properly sized for your breasts. Also, membranes or valves (depending on what type of pump you are using) need to be replaced periodically or your pump can lose suction.
My baby spewed spit up like crazy when he was little. It was sometimes much worse for my son after nursing than it was after bottles too, and I think that may be due to my overactive letdown (but I can't say that with certainty). At any rate, as long as there isn't any pain with the spit up, it's not something that warrants concern.
K. Sophia - Mama to my little lactivore, the amazing Mr. X (11/10).