Just so you know your workplace is supposed to aid you in allowing to BF, by providing time and place to pump.
If this is absolutely no option, I would suggest pumping during the night when babe is sleeping.
I would and still get my most milk then.
Also if you are going to be not feeding/pumping whole at work then your supply will drop.
But always remember whatever is good for babe - if you need to give her 2 bottles of formula then don't feel bad.
I've been mixed feeding with periods of exclusive BF of up to 3weeks.