Inconsistent Supply

This is my first week back at work since I had my daughter, so I am pumping a lot more than I used to. Before I was just pumping a few times a day after feedings to get a store of milk in my freezer, and I would typically get a few oz per pumping session. Now that I am back at work I’m pumping every few hours and getting maybe 20 mL per breast during the day, but in the morning when I pump after her feeding I will get 2-4 oz per breast.

Has anyone else had this problem? Will I start getting more as my body gets used to the pumping schedule?