Why did I dream this?

I had the most fu**ed up dream, I had a dream that me and my 2 friends were running away from some guys shooting at us at our new school were going to next year, and that we ran to my house and we hid then they guys broke in I called 911 but only one cop showed up and he saw us hiding and he just left, and on of the guys broke in and said im gonna kill you, then i tried calling 911 again for backup but my phone wouldn't dial, then the guys was like holding us down and i was like crying begging say please dont kill us and he said im gonna kill yall and i woke up, dude that was scary is it a sign or something cause i was freak out