HELP left home at 17

I'm at my grandmas safely and she lives 6 hours away from where my parents live.. me and my mom have been bumping heads and she's been verbally just out of hand and I just can't be there and she threatens me all the time and I just couldn't stay so I left and got a train ticket to my grandmas. My mom said she's going to call the cops. What can happen? What can I do to stay? What would the cops do if they came? Will they make me comeback home , even if it's not safe ? Please please help