Need help identifying a hotkey
So, I have an older mac and use the cmd+left arrow and cmd+right arrow a lot to switch between full-screen apps and I have noticed sometimes when I am doing this I somehow switch around the order of my full-screen apps. I.e. cmd+left takes me to iTunes from Safari. Then 10 min later I have to do cmd+right to get to iTunes and I have no idea how I managed to do this. Anyone know the hotkey I am pressing to cause this to happen?
15" Macbook Pro 2.4 GHz intel core 2 duo, 8GB iPod Touch 2nd gen, 32GB Verizon iPhone 5