Don't you have any benchwork today?

Everyday, I go to lab and work my ass out, so that when I come back to my room, the only thing that I am able to do is plop on the bed and sleep. Now, once in a blue moon, I will be facing a mental block or am plainly having my period, so I don't feel like to doing any work. This is when you can easily catch me sitting and busily typing away in my laptop. I just want to left alone and without any disturbance. Now, I have a bunch of labmates who can be really caring at times. So, when they see me in front of my laptop, then the question that I most hate to hear comes out
" You don't have any benchwork today ?
I gritted my teeth, smiled and replied '' no-I dont have any benchwork today."
Seriously, my first thought was to tell her to mind her own work. I am in a very good mood to lash out at anyone at the slightest provocation today. But, it is simply not worth the energy so I decided to keep quiet. Her question sounded more like "Don't you have anything to do? or "Why are you so free today?'

This morning, I decided to put down that I was not in the mood today and am feeling lazy in Facebook. Well, that was to silent anyone who wanted to know why I am not doing my benchwork today. But, people don't usually understand that once it has been clearly stated that I am in no mood, I don't appreciate being bugged with questions like " Why no mood?"

Come on, just leave me alone. What? Is there any rules that I have to continuously work? Some other people just disappear and were never in the lab for hours, yet no one ask them anything..then. why bother me..this happens all the time.

Told you that I am in a good mood to write..