Forget the T-shirt holsters altogether, period. If you are wearing scrubs you will never be able to access that LCP, period.
Get yourself one of those belly -band holsters that velcro around your midsection like a girdle - small enough to be concealed easily under a scrub top, and more than capable of carrying that LCP and a couple of extra magazines.
The only other method of carry I would advise with scrubs, considering they utilize a 'tie-string' for a waist closure, is what has just come out for the Kal-Tec, which is a spring clip that attaches directly to the piece and allows inside the waist clip carry.
HTH. Mikey.