Help! I am very new to charting and I thought I ovulated on Day 15 of my cycle due to two reasons. One, there was a significant dip in my chart on that day, and a much higher rise the next day. But, I woke up this morning, days after my ovulation window was predicted to have ended, and had this super high temp (Day 19) though nothing in my environment changed to cause it. Could it be that I ovulated later than predicted? Or does that random postovulatory rise happen to others and what does it mean?