Breast milk issues! please advice!

Hello! My baby is 2 weeks old and I've been pumping my milk and bottle feeding her... lately I've noticed that my left breast hardly expresses an ounce while my right breast can produce as much as 2-3 oz.. so pretty much all my baby's food is from my right breast alone. I don't feel any lumps or ducts when I feel my left breast, I've been massaging it regularly while in shower and before pumping... no use... is this a concern? Anyone else on the same boat? Please help!