Hi Prama
1. Is there any chance that something was wrong with your thermometer? Or were you cold when you woke up?

2. I think you can manually override FF and/or change the O detector to "OPK" only, this should take you back to the original day.

3. If you are member at FF you could try asking the FF guides. They are very helpful and have seen lots of charts, they might have an idea of what's going on.

I guess the only thing is to wait and see, which I know is easier said than done.