A-Z,
Most of us get what's called shadows before our CH starts. A shadow can be lots of different things. We feel bad, but don't know why. We have a weird feeling in our head around where our CH hits, but it's not painful, just a weird or bad feeling. Others have light pain in the area of our CH. Others get jaw or neck pain just before or at the start of our CH coming back.
What you describe sounds like a type of shadow.
I'm sure others will chime in here with more info shortly.
PFW (pain free wishes),
J