If you need to pump at work, then try to do it in a discreet and comfortable place. Usually, most of the companies offer their female employees pumping and nursing areas. In case your office doesn't then request the HR department or your manager. You can gain access to a private area for some time. And request the other employees not to enter that area till you're done with the pumping. For instance, if you have to pump in a washroom then sit on a comfortable chair and do so.