Help me understand OPKs

Shannon

Ok I need some insight. I should be ovulating in 4 days. I have been tracking daily with ovulation strips. The line seemed to be getting steadily darker each day, even though technically still negative. Yesterday and today the test line seems to have lightened. Is it possible that LH levels dip before they surge? Last month I had a clear surge, but didn’t notice a dip beforehand. Is this something anyone else has noticed? I’m obviously going to keep testing and watch to see if I do get a surge when it’s expected in 3-4days, but no I’m prematurely worried I might not ovulate this month if it’s lightened/dropped at this point.