I'm trying to prepare for going back to work. I'll be breast feeding when home and pumping at work. My question is, how did you store and transport your milk home from work? If I pump do I stick the bags in the fridge at the office and then pull them out to take home in a lunch bag with ice packs? After that are they still good to go in the freezer or do I have to stick them in the fridge for use the next day?