OPK and ovulation and sex - confused!

Peach

So I had my first at 39 yrs and my second and 42. Both times I got pregnant on the second cycle of trying. I know we are *incredibly* lucky.

Our relationship is not in a good place and we’ve been in therapy for years - but I’ve been contemplating whether we should have a third. I took an OPK test Friday morning completely randomly. It was an old test that I had from probably three years ago. I was thinking it would be a few days before I would ovulate, because my period is very regular. BUT the test line was very substantially darker than the control line.  a clear positive. I was a little surprised.

And then Sat or Sunday morning (don’t recall which) I took another old OPK that I had on hand, just to sort of check my cycle, and the test line was super faint. So I’m thinking I ovulated and it’s now the safe zone. Definitely was a negative result.

My partner wanted to have sex Sunday evening, and since it has been 3+ yrs since I really looked at trying to conceive and ovulation dates, and bc the second test suggested my LH level was low, I did not use protection or suggest that we should (this is my existing kids’ dad btw who lives with us all). 

Monday morning I started feeling a little bit uneasy about it because I had not expressly mentioned to him that I thought I had ovulated recently, even though I thought it was after the main window and pretty safe, so I started looking online and I realized I’d forgotten the 24-48 hour window for ovulation after a positive OPK test. But we had sex Sunday night and I got the very clear positive test early Friday morning, then a clear negative after that, so I wasn’t too stressed about it. That’s outside the window.

But just to assuage my anxiety, I took another OPK test on Monday morning - and much to my complete surprise the test line was just as dark as the control line. It wasn’t darker than the control line like when I got the clear positive, but it was *way* different from the clear negative. 

So now I’m completely confused. What the heck. Why would I get a clear positive then a clear negative then a very close to positive OPK? Is this related to getting older?

Thoughts?