is my boyfriend cheating?

So lately I have noticed that my boyfriends phone is always on silent . I ask him why it's always on silent he says I don't know I think I accidentally set it on there and then while I saw him on his phone I texted to see if he changed the messages from popping up where u can see them and when I did didn't see or hear it go off then texted him again to see if it would show up once he shut  it off didn't pop up I mention to him that I texted him something cute and asked why it didn't show up he got all mad about it he also changed his Facebook password after he knew I had it . Am I being paranoid or does it sound likes hiding something??