Unless you're a member of Law Enforcement; following, chasing or confronting someone who has not caused you or someone else bodily harm or attempted to cause you or someone else bodily harm. While you are carrying a concealed or deadly weapon will be considered an aggressive act in itself; because that act alone automatically puts that person in fear of their life.
Basically, following an unknown person while you're carrying a deadly weapon, should be seen as an aggressive or threatening act because you are putting that person in fear of their life. And you shouldn't be allowed to claim self-defense should that person end up dead as a result of that act.