Storing milk

So I was breastfeeding but I have flat nipples and the shield is annoying cuz my LO rips it off with his hands and fusses at nighttime feedings so I've been pumping into storage bags. He's 12 days old and seems to only drink like 2-2 1/2 oz but I produce so much milk that I'm pumping off 4-5 oz and storing it as well. Is that okay to do when my supply hasn't been regulated? I'm building quite the freezer supply. I pump every 2 1/2-3 hours and he eats every 2 hours