For those of you who pump: how much of a fat layer are you getting on your milk? We are taking a break from BFing so my nipples can heal ... We are pumping as much as I can, and supplementing with formula. I noticed that my baby seems hungrier on days that she receives mostly breast milk (which I know is normal), but I also noticed that the fatty milk on top is only about an 1/8 of the liquid in the bottle. Wondering if that's light.