Generally, I'd push on and carry on working even if I dread it.
However now I take that cautiously as a signal and step away for a while to see if I feel miserable for a longer period of time, or if I simply need rest.
I spent the day catching up on email newsletters from people I admire and reading books on my kindle.
It was beautiful.
Let's see how I feel tomorrow. If I'm dreading the thing I want to do for days, I'll definitely need to rethink my plans.