Uneven supply

I'm exclusively pumping because my daughter is in the NICU. I had a clogged milk duct in my left breast that took me a couple of days to work out but since then I noticed a drop in supply in that breast. I pump every 3 hours. My right breast will produce 3-5 oz but my left will only get 1.5-2 oz. I had a good even supply for almost 3 weeks until that clog. Any tips to help even out my supply?