Concealment is tough with people you see frequently. Someone spots a suspicious bulge at the grocery store - so what you will probably never see them again.
Coworker spots suspicious bulge and they can be checking you out potentially every day. And did I mention people in the office talk, talk, talk.
So if I wanted to be sure, as possible, people I am around every day don't know I am carrying, I would consider pocket carry, with maybe larger piece in vehicle.