If you look at my chart, you'll see that I had a big spike day after o, and then 2nd day after o, my temp dipped below coverline before spiking up again. It almost looks as if I didn't o, except that my mucous pattern and o pains indicate that I did, in fact, o. It took a few more days of high temps to settle on the o date, but myself, ff, and ovusoft agree on the o date. If I wasn't charting my cm, then ff/ovusoft may have mistakenly decided that I o'd on cd13 rather than cd11. Does that help, or just confuse the situation more?

I actually had a fallback rise with my 2nd pregnancy as well.
Since you got another positive opk today though, I'm thinking that you're either o'ing or about to o. Looks like you bd'd today, so your bases are covered either way.