Why is my iphone making the message tone but no message?

My iphone, for the first ever time made the message tone and I have no message? There's no app on my phone that makes the same sound either I have checked, apart from tweet on settings, but I don't even have twitter… I received a message 20 Minuits before this happened but I read it and replied… I have a lot of storage on my phone so it can't be that either… So what is it?

I know it's a pain isn't it. I think it's just all apple devices (iPads, iPhones, iPods) that do this

  • Why won't the ring tone on my iPhone 4 work? I got my brand new iPhone 4 the other day and I keep trying to set a ring tone on it, and when I select the one I want and someone calls, it won't ring. It won't even vibrate when I put it on vibrate. Its brand new, never been used, so I don't think it could be broken. Maybe its on a weird setting. Either way, when someone calls or texts me, I won't know because I can't hear it.
  • Why isn't my text tone working on my iPhone 4s? It's a brand new phone. The volume is all the way up and all of my other tones work fine. In the settings, it indicates that it will both play the tone and vibrate when I get a text. It does neither.
  • Why i can't put tone on my iphone 4? I try to put ringtone on my iphone 4. And everytime i hit sync it. It say the it will delete all my song if i sync… But i don't want to delete.cuz i pay for all that song… What can i do help me please
  • Why does my IPhone randomly play my message tone? It's an iPhone 4, I've had it for around 3 years and its started not so long and doesn't happen everyday or week even, just occasionally I'm not sure if it does when I'm on it or just at anytime, I mostly notice it when I'm on it, but I believe it might of happened when I was not using it Is it broken? Does this happen to other people iPhones?