For what it's worth....I think we can expect changes to our cycles as we grow older (and not necessarily ones we like). I remember a friend who reached 40...have massive changes and her Dr. indicated it had to do with her age..

This definitely can't be an 18 year olds situation though!!

If this is a low carb related problem...I'm sure someone out there will have asked their Dr. and they'll be able to share that knowledge.

I'm curious too.