Did I O on CD16 or CD18?

[SML27]

Chart expert help needed please!

My chart is here.

So, as of yesterday, FF had me ovulating at CD16, which meant I had perfect timing with BD'ing and I would have been 7dpo yesterday.

Today, I put in my temp (36.71) and my CM (Creamy), and it pushed my O date to CD18??? What gives? That means the BD'ing isn't as perfect as I had hoped, and I'm only on 6dpo today.

Why would it have changed my O date, and do you think FF is accurate?

[lyterae]

I'm not certain why it moved O day for you, I agree with CD16 though. Also though, if by some chance it wasn't until CD18 you still have good timing.

[GaleTX]

Mine has changed several times on FF this month. It said day 17, then changed it to 15, then back to 17, back to 15, back to 17! I know if you do the tutorials they say they don't base it just on one factor (temp, CM, OPK, etc.) and they are constantly re-evaluating data as you enter new data. I wouldn't put too much stock in it until you go several days without the O day changing. But either way, your timing is still good!