How could I have accidentally begun my turn?

I was happily typing away in game chat today, when to my horror I saw that I had begun my turn! As this was a team game, and I had not heard from my teammates yet, very uncool
I've never done this before - but I am a terrible typist, and could have easily hit some random keys by mistake...
My question is: if I want to ONLY start/play my turn by clicking on a box, or a drop down menu, is there a way to disable any other ways to start/play?
And what did I do to cause the game to start, anyway? I'm now totally paranoid about typing in chat...
thanks!

I've never done this before - but I am a terrible typist, and could have easily hit some random keys by mistake...
My question is: if I want to ONLY start/play my turn by clicking on a box, or a drop down menu, is there a way to disable any other ways to start/play?
And what did I do to cause the game to start, anyway? I'm now totally paranoid about typing in chat...
thanks!