hi Kat

once my temps rose two days in a row (about CD 20/21), FF marked CD18 as O day on my chart. But then when temp dropped slightly the following day... FF actually changed my O day, saying it was CD16! I have never had that happen before (and am a little skeptical I have to say). Now I am on CD26 and temp has gone up up up last three days. Feeling exhausted but not cranky, which is unusual for me at this stage of my cycle... so fingers crossed!
You can see my chart here:
2f430a Ovulation Charts

Will be interesting to see what happens for you. Are your cycles usually fairly consistent each month?

LMM