How's your baby's weight gain and urine output? If it's ok, means you do have milk supply but an issue with pumping? Check that the mechanical pump is still working well if you are using your pump from the days of your first child, or even change the pump. Given that your child is only 1 month old, I'll focus more on latching to get the milk to come in. Remember to latch at night as well as that's when milk production is the highest. The link below may help you.
http://kellymom.com/hot-topics/pumping_decrease/
Anonymous