my ex-girlfriend is stalking me

Tweet

i had this girl i went out with for a couple of years , i broke up with her when i found out she was cheating on me and had three other guys and worst of all,we the guys all knew each other. I broke up with her and now i'm in a very lovely relationship and she's back at my doorstep begging. What scares me the most is that she hangs around my office parking lot at night, she drives behind me onmy way home and even parks a block from my house and watches me from afar then she just drives off. what do i do because my girlfriend is getting really freaked out at this. i need some advice should i tell the cops.