How long did it take for you to fully establish milk supply with your preterm baby?

I had my baby at almost 37 weeks and I’m really struggling to get my supply up. She isn’t getting anything from latching and is bottle fed. I’m using every supplement and strategy you can think of, pumping every 2 hours and power pumping daily. She is 2 weeks old and I’m barely producing 1.5 oz each session which isn’t enough to feed her.

I still haven’t hit my due date with her. My pediatrician said it may take until her due date for my supply to establish but 2 weeks in of consistent stimulating, I don’t know what will suddenly change a week from now. Did anyone’s supply actually come in this late/after hitting their due date or am I most likely only going to have gradual increases from this point forward?