Are any other breastfeeding working moms having trouble keeping up their supply? All I seem to be able to pump is 12 oz the whole work day, which has been fine until lately. My 4 month old seems to need more during the day now - 15 or 16 oz. I'm trying to exclusively breastfeed until she is 6 months but I'm wondering if this is a lost cause and I should just supplement with formula and not worry about it? Or if my body will catch up to her need soon? Any words of wisdom?