12-14dpo, BFN, what’s going on?

Would love some advice. Normally have 28 day cycles, today is CD29. I thought I ovulated (based on bbt) on CD15, which would make today 14dpo, and the day AF is due. A different app says I ovulated on CD 17, with AF due in 2 days, but even then, I’d be 12dpo so should have gotten a BFP.

I’m not sure what the likely scenario is...is it more likely I’m having a cycle that is 2+ days longer than normal (no AF signs), or that I could be pregnant but with a BFN at 12dpo? Help please!