My baby is 3 weeks old and I've been breastfeeding on demand around the clock. When he's napping, I try to pump so my husband can possibly help with feedings at night. Baby latches well, eats/poops/pees/sleeps fine, has gained weight, but lately I've got nothing coming out of the pump! Obviously I'm producing enough milk to keep baby happy, but don't get why I can't pump anything anymore. Is it because I am feeding him on demand or am I not making enough? Thanks!