Ovulation/OPK Question

Just trying to make sense of this... once you have an LH surge and your opk tests positive, you will ovulate in the next day or two. So basically when your opk is negative in the day or two following the last positive is when you will ovulate?

Last month I got positives for about 2 1/2 days before it finally started being negative again. The months prior to that I stopped testing once I saw the first positive because I never thought the surge would last that long. Just trying to pinpoint ovulation to increase our chances the most.