Jolyn, when I started charting cycles on FF (only start of periods) I went through a patch of cycles that were only 21 and 18 days long...then a couple of 23/25/24/26 and then 3 months of 27 and now it seems back down to 26...
I think your body does tend to "shift" itself now and again and then it rights itself...so don't panic if its a little off here and there!!!

