If you BF, when did you start pumping?

I have a couple of work meetings I can't get out of and will need to leave LO at home for within the first month. Likely she will need some pumped milk during those times so just wondering when everyone started to pump and how they fit pumping in with the feedings to get some extra milk for such scenarios.

I have no clue about pumping and feeding so any and all information is welcome. Thanks!