Pumping at work help

I just stared back to work last week. My son is 7.5 months and breastfed. I never really pumped before but never had supply issues (luckily... my first was not so easy). The first few days I pumped about an ounce more than he drank. Now he is eating about 4 oz more than I am pumping. Do I need to do something to boost my supply or will it adjust? I had about 30 bags in the freezer from using the haaka or randomly pumping over the 7 months, so I still have a bit but I want to keep up if I can! Thanks!