I did the clear blue ovulation test kit and even with a 28 day very precise cycle, I ovulated about 5 days later than the calendar prediction. I assumed that meant that my dating scans would be off by about 5 days. However, my daughter's development is consistently showing 4 days AHEAD of schedule per her organ development and otherwise...as if I ovulated 4 days EARLY, not 5 days LATE. I'm going to ask my dr at my follow up visit but just wanted to know if anyone else had this experience?