Hi A.,
I'm the mother of two children who were preemies (28 weeker, and a 34 weeker) and I've so been there with the pump/breastfeeding issue. Right now, while he's so little, I'd pump all you could to build up a supply in the freezer and help keep your supply up, too. With preemies and pumping you are facing an uphill battle but it can be done! When he is big enough to latch on and not waste too much energy trying to breastfeed, I would be there for every feeding (I assume he is still in PICU/NICU? or is he home now?) and have the nurses let him try breastfeeding for a few minutes first.
With both my boys, we did have trouble nursing in the long term because they were so used to bottle feeds.
In the end, I had to continue to pump for a year at home with each boy, and while they would nurse some, they had continued confusion and I ended up feeding them both fresh and frozen breast milk. All in all, I decided that the things I wanted most were to get the breast milk into the baby, and to bond with nursing as much as possible, and even though it wasn't perfect, I felt pretty good about managing those two things. :) It can be a hard thing to teach preemies to nurse properly, but with the right support (and continue to pump after they nurse to keep that supply up... get a medela pump in style or a hospital grade pump for rent to take home with you, those are the best choices in my opinion!) you can have a very successful outcome!
Sending blessings and hugs to your sweet little one!
L.