Positive OPK - negative OPK - then positive OPK again??

We have been TTC for about a year now. I started on Letrozol in June. This month I was told only to take 2 tablets, cause my gyno had summervacation throughout July.

Last cycle I got positive opk on cycleday 16, AF came on CD 32. (Wich was 3 days late. Something she almost never is)

So this cycle I had my a postivie opk late sunday evening CD 13. It stayed postivie through all Monday, turned slightly negative (like 1/2 shade brighter) through tuesday, and was positive again this morning.

Can it be that my body tried to Ovulate, but couldn’t release an egg, then tried to ovulate again?

I’ve had postive opk for like 2 days earlier, but when it got negative it never became positive again.

I’ve tried to messure my bbt but it feels like i varies to much to get a full reading.

Has anyone else experianced this? Has some insight?