My baby is 1 month old & i have been pumping my breast milk to feed her but y haven't i produced any all day? will it come back or did it dry up?

Try reglan (metoclopramide): Let the baby use you as a pacifier, that might help, ask your doctor to prescribe reglan (metoclopramide).

Pumping not optimal: Pumping is not as effective in removing milk as a baby who latches & feeds well.Over time the breast may slow or stop producing as it is never completely emptied. Re-lactation is sometimes possible with the aid of supplemental hormones& frequent emptying but your system may not cooperate. Find a local breast feeding coach & try if you want.