HI,Vicky,
I had that experience too, when my bb was 1 to 2 days old, she sucked my nipple for 30 seconds then fell aslleep, nurses in the hospital said because if the baby couldn't taste sweet( means no milk ) , they'll fall asleep, so the first thing you should do is stimulate your milk .
Try to use hot wet towel to wrap ur breats for 10 to 15 minutes before you feed ur bb , also let ur bb suck more ,they can stimulate the production of the breast milk.
Medela electric pump is quit good , I used it before, and now I feed my bb directly, that's more convenient .
Hope to hear ur good news soon!!!