How do I get a preview of my text messages?

Recently, I have not been able to get a preview of my text messages on my iPhone 5s. It shows who I got a text from but it says iMessage instead of the actual text. When I first got my phone it showed who it was from and what the text was. I tried turning iMessage off but then it would just show "text message" and it turned the messages I sent green instead of blue. I want to know what the text message says before I respond. I did notice the problem a little while after I got the iOS 8.3 update if that makes a difference. Please help!