When should I test? DPO Changing

Originally, Glow said I ovulated on July 4th. My husband and I had sex on the 3rd and the 7th. We were not TTC as we were vacationing at our parents.

After vacation, TTC has been in full affect with sex on July 11, 12, 15, 16, 19, 21 (today). We weren't expecting anything as we thought we missed my fertile window this cycle. Nbd, just practicing. 😁

AF was expected Monday July 17th. Nothing.

Since selecting "period is late" all this week on Glow as I still have not gotten AF, my O day keeps shifting. It now says I ovulated on the 9th.

So without a period to reset my cycle, am I 12 DPO or 17 DPO??

I'm just trying to pin down an appropriate day to test (as I got a BFN yesterday morning).