5dpo dip well below cover line - normal ?

I have been temping for 4 months now and I haven’t had this fall well below my cover line before. I am not indicating that I am pregnant and I know many external factors can play into your temp, but just wondering is this a potential fallback rise?

My only confirmed ovulation on CD17. But just wondering about other womens stories who are temping and had this shift after O below their cover line as I haven’t had it before.

❤️