Huh. I'm stumped! The only reason a later O seems more likely based on your chart is because the temps are significantly higher after the 4th.
But, that dip on the first is really low, and the rise after is steady but slow. If that's when you had other signs of O, I think you could have still O'd on the 1st.
I think you could have O'd on the 1st. I don't think the dip on the 29th means anything - but I would wait and see what happens over the next couple days. You have dotted crosshairs- not solid plus FF changes it mind a lot. I think (if I'm remembering correctly) that when I got dotted crosshairs - they always moved the more temps I put in.
Dotted crosshairs means FF can't definitely confirm anything/ the data are contradicting but this is the most logical place for crosshairs. If I look at your chart, I would agree with that though, I see no reason why FF would have you ovulating on the 1st except for a dip the day before, but that doesn't have to mean anything. It isn't until 2 days after that dip that your temp starts rising. :-( If I'd see your chart without crosshairs, I'd put them at the same place :-(
I wonder if you get the dots because of the 3DPO dip, btw. See if you get solid lines if you discard that temp. That might tell you more. But really, if you look at that chart, the 4th is when you actually get a rise. Sorry!!!