If I have studied for a specific subject, then usually I'd be quite confident when I am doing the test, especially when I come across a question which I can recall studying specifically for. However, this exuberance of confidence has made me inclined to feel paranoid when it seems I am doing a test too quickly, and I go back and read over simple questions, expecting to find a mistake.
If I haven't studied for the test, I'll usually spend the five minutes reading time examining the test and come to a stance on whether it'll be easy or difficult. Usually when I decide the test is easy, I'll fly through it. But when I realise it is difficult, I begin to ponder whilst doing the test and condemning myself for not studying.