Hey Ellsac,
I have not been officially diagnosed with SFN but have had some tests which suggest its presence or at least some type of problems with small fiber nerves. So you asked about if others have more problems around their periods. I thought I would reply because I actually was just looking into that recently after having a lot of searing pain in combination with numbness (it was very odd) down my right leg during my first day of my period. It got bad enough that I had to leave work but seemed to dissipate after I rested/slept for a while and then hasnt been that bad since (that was a few months ago). Is this at all similar to what you experienced?