Positive OPK today and its our anniversary :)

As

I thought maybe I'd missed it in testing but I just got a positive on CD22. Its our anniversary so it would be soooo amazing to conceive today ;)

Is it normal to ovulate this late? I used to always ovulate early in my cycle but I did just get my mirena IUD removed so maybe it just changed a bit this month. I have no clue when to expect AF. I have 3 apps and they say anywhere from the 8-12th.

How do I calculate DPO? Would I be 1DPO tomorrow?