Since I have only been on this WOE for a month, I can't really speak with authority, but my last "moon cycle" was much longer than usual, and I feel it may be because of the WOE.
Plus, many women have reported changes in their cycle due to this WOE (more crampy, less crampy, longer, shorter, less symptoms, etc).
The way you eat can definitely affect your body's cycles, so it is quick likely that any changes you experience are due to LCing. Unless they are very bad changes (bad cramps, etc.) it shouldn't be a problem. Just go with the flow (sorry bad joke heh).
-Angie