My supply is going down slowly too coz now the supply is based on his demands. But before I resumed work, I had about 20 packets of frozen EBM and if I thaw 2 packets I make sure I express equivalent amount or more. On your off days, probably you want to build up your supply by expressing more and while you are nursing your baby (football style), you can express at the same time. I did that before. Might help to build up your milk bank.