Pumping for surgery

Okay ladies. I go into have my tubes tied on Thursday. My SO doesn't get paid til Friday. My mom is gonna be watching Josiah while I'm in surgery. I need ideas on something I can pump and store my breast milk in for him and keep adding to it if that's possible. I didn't think my surgery was gonna be this soon and after bills were paid, we are broke. Any idea on what I can store it in for her to be able to feed him Thursday? I really don't want to give him formula. Considering hes never had it.