Breast pump shield question

Shiney
Okay so I have really small nipples and from what I read about the smallest shield still won't be the right fit- the pump I have came with the 24 shield and I can pump but it doesn't fully empty my breast out and I only get an ounce or less. But I can feed my son on the breast I pumped and he'll be swallowing for 15-30 mins so there's still some in there.