I have been bf and pumping since day one...I, however, dont usually pump for more than 5-7 minutes (db electric pump). I have read about pumping longer, but usually around 4 minutes I have 2 oz from each breast. I pump to get 1/2-1 oz more per breast. When the milk settles, there is three levels...am I correct in assuming I am getting both milks? I try pumping longer, but it starts to hurt and nothing more comes out.
I, too, have a quick letdown and can have 2 ounces/side in 5-7 minutes. I pump for about 15 minutes in the morning before work and can sometimes get another letdown if I'm patient. At work I only pump once for 10 minutes and, even then, I'm not getting much after 5-7 minutes. I think everyone is different and this is just our version of "normal".
Re: pumping time?
I've read that if your baby isn't getting enough hindmilk their poop would be green. As long as you baby is having yellow stoles then I say yes.