Pumping amounts?!

Currently been breast feeding for about 6 weeks now and I’m able to pump between 5-8 ounces per pumping session (10 minutes) I pump probably about 2 times a day because shes eating off of me a lot so I really don’t need to pump (storing some for in case I’m not around or have to go somewhere) Is that a good amount to pump or is that a low amount? My doctor seems impressed with how much I can pump but i feel like that’s a small amount.