This is my first time tracking and I feel like I have a new question everyday.

If I look at my test from the beginning of the week, they are much darker than the ones I took yesterday or today. Does that mean I had an LH surge earlier this week? That would have only been CD8. Is it possible to have had a surge right after AF ended?

Also, are OPKs like pregnancy tests, I heard that if you look at one days later you may see a positive that wasn’t real. Is the same for OPKs?