Ok i'm worried please help?

Ok so me and my friend were talking on the phone when all of a sudden I heard this weird noise an then the phone hung up. I tried calling back she just hung up. I tried a few Minuten later it rang an rang and rang . She is not responding to text oder calls oder anything! Please I don't know what to do i'm not sure if its because i'm a extremely paranoid person oder what? Should I wait till tomorrow oder try an get a hold of her now? oder what would Du do in this situation?