First time breastfeeding

I had my lo 4 days ago and she’s been in the nicu so I’ve been having to pump and supplement. I’ve been pumping every 3 hours for about 30 minutes. I pump for 15 and hand express for 10 and pump the last 5. I’m only getting about 5ml per pumping session. Is this normal? I don’t think my milk has come in yet. It’s still a yellowish color but more liquid than it has been. I’ve been drinking a ton of water and eating plenty of protein and oatmeal. How do I increase my supply or is that a good amount for how old she is? She eats 50ml every 3 hours right now.