iMessage won't notify me that I got a new message

IMesaage won't notify me my new message. It do come up on the notification screen, and won't vibrate or show at the top of the screen or lock screen. I have to go to the messages and see if i got one. It shows me how much I have for new messages, but doesnt notify me if I have one. Please help! I have AT&T IPhone 6 iOS 9.0.2