The one-sided pain I get (right hand side) appears to be linked to my nerve pathways. I always got bad headaches on one main spot, and then numbness and/or pain through my cheek, jaw, shoulder, arm and leg on the same side. I also had what seemed like distinctly different types of pain at different times, but always in the same
locations.
On the plus side, this has reduced massively through antibiotic treatment to the point I am now only getting pain just before my period or when I am unwell or particularly tired. So - it will get better over time...