Is he cheating?

Caitlin
Ok, sooo I moved in with my fiancé over a year ago and we're supposed to be getting married in June of this year. Up until the past few months he's been sending off weird vibes as being sneaking and deleting messages and stuff like that off his phone. It's weird because he wakes up around 2:30-3:00 EVERY morning and always turns me away with my back facing him and puts his knee on my back so like he doesn't want me to turn around. Well I turned back around when he did it this mornin and he was on his phone with it turned to where he thought I couldn't see anything on the screen, but when I turned around he immediately pressed the home button on his phone to get out of whatever it was and went to a different app. But there has been many times where he doesn't want me to use his phone and he has also recently taken my thumbprint off his phone. What do I do ladies?! My nerves are torn to pieces!