If you feel confident in your ability to draw, fire, and hit your target under stress then go ahead and carry. A smaller pistol will be better, of course. I carry a pistol sometimes, and you definitely want to use an on-the-body carry method. There are concealed carry fanny packs on the market. Get one of those---the one that has a quick draw flap. There are some that unzip just like a regular fanny pack. Those are too slow. You want the one where you pull down on the pack and the velcro comes apart, providing access to your handgun.