OPK after chemical

For those of you that use clearblue advanced... I got my first day of "high fertility" today at only 9 days into my cycle. Usually the first day of it isn't until CD 12 or 13. I had a chemical pregnancy last cycle (first month TTC) and my period was much heavier but MUCH shorter than normal. Is it normal for your high fertility days/peak days to fluctuate month to month? I'm also wondering if this happening early might mean I'm about to release 2 eggs. I have had cycles where my high fertility phase was 11 days before peak, and the doctor told me that meant multiple eggs (so if we conceived: twins). Any thoughts? I usually have a fairly regular cycle going between 28-30 days in length.