Pumping at Work

Katie.
Hi mommas,
I'm about to return to work next week and anxious about breast pumping at work. I work at an office job with a shared fridge. Do you pump in the bathroom? Do you store your breast milk in the communal fridge? What happens if you're off site for a day where there's no private room? Do I go into the bathroom and do it? What if there's no electric outlet to plug the pump into? Also, did anyone buy pump bags to store the milk or did you store it in those bottles? 
What's the most quiet pump? I currently have a medela pump but it's loud, is there a more quiet brand on the market?