I'm going to separate this question of "when did you become comfortable" into two separate questions.
1) When did you feel comfortable carrying your weapon concealed? After a week of practice at home, before my license arrived, and neither my family nor friends noticed I was fine. After my permit arrived, immediately. And when I switched from my SERPA to my crossbreed, the whole rig became as common as my cell phone. The more invisible and comfortable the rig is, the more comfortable you are with it and won't worry about printing.
2) When did you feel comfortable carrying your weapon with one in the pipe? Short answer is about a month after I received my CWP. Several trips to the range while carrying "condition one" and piddling in the garage in "condition one" helped ease my mind that this gun won't go off unless you make it. It's the only way to carry, IMO.
SC CWP
NH non-res CWP
NRA Member