So, I have a great pump, the PIS double pump. Anyway, I SAH with both my kids, but I'd like to build up a supply so I can leave the baby with a sitter at some point. I can't figure out how to get started though! Every time I pump, I end up having to give the baby the bottle that I've just pumped because I can't produce enough to make up for it. When is the best time to pump, and should I do it daily even though I don't really need to? Other people have told me just to pump before I leave or pump only when I need to, but I can't see how that works..isn't it a supply and demand thing!?