Chart confusion

Hi ladies! See my attached chart. So it's my second month using opks and I tested 3 times per day on cd12-14. On Monday (cd 13) I woke up and my temp dropped. my opk was negative in the morning, almost positive at 1:30pm and positive at 6pm. On Tuesday morning, afternoon, and evening (cd 14) my test was still very positive, but my temp was back to my usual 97.5. I assumed I o'd on Tuesday night or early Wednesday since my opk was negative by morning of cd15 but ff shows Monday. Is that really possible?