Advice? How did you increase your supply to get a freezer stash going?


My son is 7 weeks old and I was pumping every 3 hours in the NICU and once he came home at 2 weeks old I have pumped less and less but am exclusively breastfeeding now, only a bottle (breast milk) right before bed for dads bonding time with him. I'm worried I'm not producing enough to pump after feedings anymore because after 15-20 min of pumping I am only getting an ounce or so all together and I can only pump 3 times per day because my son is hard to even put down. How do I up my supply or is this normal? I'm getting about 3-4 ounces a day in my freezer, but I really want to build a stock pile in my freezer for anytime I want to leave for an errand or something and am not back for a feeding or anything like that?