What does your refrigerated BM look like?

Hefinallydidit

I expected my breast milk to have more fat but the last few days it seems I have a very thin layer of fat at the top and the rest has a skim milk look.  I understand the difference between fore milk and hind milk and realize the skim milk looking milk is the fore milk.  I'm pumping any where from 15-20 mins each time.   This morning I was so full I could have pumped longer but my nipples start to hurt and had to stop.  Should I pump longer to get more hind milk (because I never seem to empty)? DS's pedi said not to worry about what milk he is getting and she is sure he is getting all the right stuff but I do worry that he isn't getting enough hind milk, especially after seeing the milk separated.