Not enough supply

Ebony
So I had my baby boy at 37 weeks Oct 29th and my milk didn't come in until 2 weeks later and he's 4 weeks now and he latches on but he's not really getting any milk I pump and barely get 2oz of milk and that's from both breast so my question is how can I get more milk for my baby? And have any other mommy's had or have this problem?