Why does my iphone screen not light up or make any sound when i get a text?

So my iPhone 5 will ring when someone is calling me and when I put an alarm on. But whenever I have a text come in the screen does not light up and it does not make its usual sound either. I don't know why its doing it! It started a couple of days ago.
I've made sure the ringer is on every time and its turned up on full!
If anyone has a clue that'd be great!

Go to settings<sounds<text sound effect<on<then choose your sound effect and your done but make sure your iPhone is not on mute or speaker is broken

Have you tried turning it off and on again? Also, are you acidentally turning it to silent mode?