以“An unhappy day”为题,写一篇语意连贯,语法正确的短文

Today is an unhappy day.Actually it is the most unhappy day in my life.You know what.I got an hour free time detention!Do you know what that means to me?It means that my recorder in our school is not pain any more.Oh,Gosh!I hate this feeling.What?You asked me what happened today?Let me tell you.Our Math teacher is always late for class.I have already used to fitting in her lating.But today,she didn't late.It was so surprised that she was on time!Then,bad luck came.As I thought,she might be late today,so I went to class seven minutes later.But she gave me a detention,the reason was that I was late.Hey,what's wrong with her?When she was late,she said nothing.But when we were late,she gave us detention.She seemed to be very happy for giving us detention.That's unfair!