I've been running around to the store, the bank, and everywhere else with just a t-shirt over my Baretta PX4 (14+1) IWB at about 4 o' clock. No one has said anything. Only time I felt nervous was that other day when it was really windy.
One of my room mates is terrified of guns (can't they just go off?) doesn't know I carry, they haven't noticed either, and I'm always carrying.