I had a similar experience a year ago when my baby was also in the NICU. The hospital was able to freeze it so he would have it after he was out of surgery. Additionally, if you're planning to breast feed your body needs to know it's correct in producing that amount of milk. Therfore the best thing is to pump and freeze it so it will be able to meet the needs of your baby when he's doing better and out of the NICU.
I wish you all the best and a speedy recovery for your little one. It was such a emotional rollercoaster for me and my husband, but now our bundle is running all around the house cause mayhem :)
Thanks so much! Surgery went well and the pain went away after 2 days of constantly pumping lol God bless :)