Getting Pepper Spray To Feel Safe

I work in an urban area and park my car in a ramp. There are many nights I work until long after dark and while my buildingis secure and the office where I work is locked, I still feel vulnerable while I am walking to my car. I would like to feel as if I had a chance against any attacker that could be lurking as I unlock my car door. I got a small container of pepper spray to keep on my key chain so it will be in my hand if I am walking to my car. Now I feel I have a chance if the unthinkable happens.