Occassionally our 4 week old sleeps past 3 hours, should I pump a little at the three hour mark or just nurse her normally when she wakes up? I'm torn between breastfeeding 'on demand' (which I think would have me wait) and keeping my supply up (it's been good so far and baby is gaining plenty of weight - I'm a little paranoid about messing up my supply since it has been good). Or should I only pump if my breasts get really uncomfortable? Thanks for help!!