You know, you do have that strange shift in temps that FF calls your ovulation temp, but then the temperatures go back down again and you have a second thermal shift later on... and you were still experiencing eggwhite mucus, which would have dried up had you truly ovulated when FF said you did... You know what? You could be only like 13DPO right now, if you ovulated on CD30. The fact that you had all those negative tests and didn't start showing positive until the last couple of days also could support this.
I think in your case that (God willing) if this pregnancy sticks, you might want to consider going in for a dating ultrasound because if you did ovulate that late in your cycle, your due date will be "off" by over 2 weeks!!!! That will make a HUGE difference.
Hoenstly it looks like you ovulated late. Like 16 days late.
The more I look at it the more it looks like you maybe didn't even ovulate until somewhere around day 30 of your cycle. Because the temperature shift at CD31 is accompanied by your mucus drying up as well... and usually the sign of ovulation is a *sustained* temperature rise *crosschecked* by a dry-up of mucus, which doesn't happen in your case until CD31, etc.