If it's just something you do when you're bored, then it's very unlikely. It's when it gets to a point where you're doing it all the time, for no reason whatsoever, although it may appear that there is a reason.
And, usually, there's more to OCD then just one thing like counting.
If you like, here are some links with information about OCD.
So, unless more then just the counting applies to you, that is in those articles above, I wouldn't worry about OCD, as you probably don't have it.