Re: why keep pumping?
I don't do it either, but I think it signals your body to make more milk the next day at that time. Kind of like when your baby is going through a growth spurt and sucking and sucking until your body gets the picture to make more milk. I had to do it when my daughter was in the NICU at first - I guess to get my milk to come in since that is what she would be doing.
I have pumped longer than normal a few times at work and just kept getting milk out. So I'm not sure how long one would have to stay attached in order to pump after there is no milk.
Lilah 10/08 nursed 25 months
Beatrix 01/11 nursed 30 months