I have a question: do therapists have to report threats made on you by another person?

Without getting into too much detail - The threat isn't something that would appear as a threat to anyone unless they actually understood the situation... I received a letter in the mail from a person I have been no contact with for the last 2.5 years. They are not supposed to know where I live and I have no idea how they found out. All the "letter" is is a printed airline itinerary that says "See you soon." So it's not a threat on my life or anything, but this person has terrorized me for many many years and contact with this person is never not dangerous... To me the "letter" is a passive-aggressive threat.

Would my therapist have to report this to the police if I talked about it with her? I really want to but if anyone is going to get the police involved, it's going to be me, not her. I am not a minor and I have absolutely zero intention on meeting this person face to face (if/when they show up to my place, the cops will be called if they refuse to leave my door step). I live in NC, USA if that matters.