Phone call scared the shit out of me

[Technomage]

I was driving to school on wednesday, and while driving i was listening to music, and suddenly the music stopped and I heard a phone ringing, I tried to look for my phone and I looked at it and it wasn't ringing then I noticed the dash and saw a phone icon, i pressed the phone button and someone started talking, I was like holy shit. This is the first time i've ever experienced this, I don't have bluetooth in the car, and I never know the car had a phone, is this normal. Its scary on the highway going 80mph and hear a loud phone ring.