Mrs. K, most of us understand how irregular our periods can be with PCOS. A lot of women "normalize" their cycles within a few weeks (even days) on an LC diet. If you are losing fat, then your cycle can always change a bit because estrogen is stored in our fat cells. So losing weight can disrupt the natural flow of things. When I first started this WOE I became regular and after losing about 20 Lbs I noticed that my periods were coming earlier and earlier. That went on for about 2-3 cycles and then they went back to 27 days. I was on pills (orthocyclen) and I would get my period during the middle of a pack. At first I was worried but I talk to my doctor and realized that weight loss was the culprit. If you begin to feel too uncomfortable or if things don't change after a time, I would advise you to see your PCP.