If it says there are 2 there probably isn't. It won't update every second. We have too many people across the network now to show view counts and post counts bang on.
I have about 250 all the time I can't get it down.
But if you're in single numbers, then go read them, then check again, it might not have updated yet.
But by the time it does, there might be another few.
Clicking the mark forums read forces and update so that will be accurate and zero then.