Breast Milk Supply

I'm a first time mom and I feel like I'm having issues with my supply of breast milk. My son is in the NICU mad has been there since the day he was born, he's three weeks old today and is still not being fed because he's sedated. I pump everyday and at first when my milk came in it was a good amount but as I've kept pumping and never actually breastfed my supply is tapering off. Is there anyway that I can keep it up? I don't want to stop making milk before I can even try to feed him.