Howdy BlazinDei,
It sounds like you have a video that is showing an incorrect thumbnail image in your Videos app. I would start by quitting all the running apps on your phone:
iOS: Force an app to close
http://support.apple.com/kb/ht5137
Double-click the Home button.
Swipe left or right until you have located the app you wish to close.
Swipe the app up to close it.
When you have done that restart the phone and test the issue again:
iOS: Turning off and on (restarting) and resetting
http://support.apple.com/kb/ht1430
If the issue isn't resolved after these 2 steps, is the video one you took with the camera, or downloaded from iTunes?
Thank you for using Apple Support Communities.
All the best,
Sterling