Best portable pump?


So my work is only giving me two 10 minute periods to pump in a 6 hour shift and I do not want my supply to dry up once I go back to work, I’ve never pumped before as this is my first child but I was wondering if anyone has ever pumped while working by using a pumping bra, pulling down the shirt and getting work done or if that’s even possible (sorry if this is a stupid question) what pumps would you recommend if this is a possibility or just a nice portable pump In general, thank you :)