Yesterday, I was feeling sick. I had a headache and was unusually tired. I wasn't getting any work done, because I couldn't concentrate. However, when I brought this up with my boss, and then left early for the day (one hour and thirty minutes early), I got the distinct impression I had done the wrong thing. Even though he said almost nothing, it was a stressful conversation for me. This was the first time I've done this, so I wasn't sure of what to do.
My reasoning was that going home and sleeping would help me recover by the next day (today, and while I'm still not great, I am much better), whereas staying at work, which I certainly could have done, nothing would have gotten done, anyway.
How sick is sick enough to leave early? When should I just tough it out?