Feel pain? Should you workout?

The empty workout room (see picture). This is how this room will spend Sunday. Why? I woke up with a slight lower back ache and today is back. Its probably just stiff but why tempt fate.
It's okay to skip a day if you're nursing pain or perhaps you are mentally not prepared.
In most programs you are given a rest day. This makes it easy to occasionally postpone a workout.
So be smart and workout wisely.