New to breastfeeding

My baby was born 6 weeks early and is still in the NICU, and I just got discharged from the hospital today, but my son will be there for a while. I've been pumping religiously to get my milk in and luckily I've got a pretty good supply so far, but I've noticed my breasts are still really hard even after pumping. I've been getting about 2ounces every time I pump combined from both breasts, I just don't really feel relief after pumping. Hopefully tomorrow we will try putting him on my breasts, but is there anything I can do to help with them being hard? I've been pumping every 2-3 hours. Thanks!