Returning to work

At 12wks I'll be going back to work (ugh). I'm EBF, and really worried my supply will drastically slow or stop when I do since I'll no longer be around my daughter. I thankfully work for an amazing place, so I have my own office and can pump when needed. Any tips for returning back to work? Did your supply slow when you did? How often were you pumping? I figured I'd pump 3x per day? As I work 7am-4pm. Thank you.