BBT charts: implantation dip? Triphasic??

First, why does app suggest ovulation occurred on the 4th? I would've guessed the 2nd. Opinions?

Secondly, my bbt took a sharp dip on the 8th days after ovulation already occurred. Then today it went to the highest I've ever charted before. I did some internet searching and apparently there's something called an "implatation dip" and also a "triphasic" chart. Anyone ever heard of this? I'm hopeful but I bet I'm just reading into too much. Still, I didn't know about it until after it had happened so I don't think I'm subliminally reading into it but who knows. Anyone else with a similar chart? Could it indicate pregnancy? I used clomid and hcg trigger this month, too. (Hcg trigger was on the 2nd, btw.)

Thanks for your thoughts!

April