If you're carrying a gun, you should be carrying pepper spray. Period. It's cheap and it's usually effective, and it gives you an intermediate option which you need. It's not that uncommon for an unarmed person faced with a gun to cop an attitude and dare you to shoot them. Some posters here will tell you that lethal force is then justified: that kind of thinking will get you sent to prison unless you are a 75 year old man or woman getting pummeled senseless by an 18 year old thug, and there's video to prove it.
Lots of people who have never pointed a gun at anyone in their lives think they can pull the trigger without hesitation on an unarmed assailant. Not likely, and the perils of hesitation at close quarters are obvious. You're much less likely to hesitate with a non-lethal option like pepper spray, however, because you know it does no permanent physical damage.
Pepper spray impacts your ability to breathe deeply, which is great, but even better it causes your eyes to involuntarily squeeze shut, effectively blinding you. I'm a LEO and I've been sprayed a couple times in training, and I've used the stuff for real with good results. People don't drop to the ground like on the commercials for the stuff, granted, but it ruins their day.
Look around at the young ladies the next time you go to the coffee shop or wherever. You'll see pepper spray canisters dangling from some of their purses or keychains. There's your jury pool if you get arrested. They're not carrying tactical knives or impact weapons. They can relate to pepper spray. Another plus.