How do you determine how long to pump so that you empty your breasts but don’t make the oversupply “worse”?

Right now my daughter is only taking 9-12oz while she’s at daycare but during that time I’m pumping 20-22oz within 2 sessions. I already cut my sessions from 3 to 2 a day but I’m still getting the same amount total. I usually double pump for 20 minutes because the milk is still flowing on at least one side.

When I first went back to work and started pumping I would get 6-8oz total for one session and now I’m to the point that I’m almost filling a 9oz bottle just on one side in a session and don’t want to have to get bigger bottles just for pumping.

Would you change anything?