Ever sound like you're guilty,when you're actually innocent?

Do you ever find yourself sounding guilty, despite not having done anything wrong? On a few occasions the fear of someone thinking I did something in a particular situation, actually made me sound as if I were lying, and practically convinced them that I did something I really hadn’t done (and trying to explain yourself from that point onwards just makes you look even more guilty)... Have you ever had that happen to you? Any ideas on why this happens? To me, sometimes, it feels like – instead of working to preserve itself – the mind wants to be ‘endangered’. Thoughts?