iPhone 4s not receiving iMessage notifications

I have an iPhone 4s with iOS 8.1.3 and just recently, iMessage is not showing any notifications when I am outside of the app. I've checked to make sure notifications are on and everything. When I am outside of the Messages app, I don't receive any notification whatsoever (not even a vibration) when a text is received. The only way I can see that I have a text is if I go into the app. Notification center also does not display any iMessage notifications, however notifications from other apps are received. I've tried turning on an off notifications, restarting the phone, etc. Any idea on how to fix this?