Frozen milk @ 2 weeks

So I exclusively breastfeed my son and he will get a bottle of formula once every couple of days (2oz) (to give my nips a break) well I have been pumping along with nursing him and I currently have 18oz frozen. Is that a good amount to have frozen at 2weeks pp or should I be producing more? I feel like I ain’t producing a lot and that I should have more frozen. For those who are exclusively breastfeeding and pumping how much do you have frozen? Also to those who only pump how much do you have saved?