OPK HELP!

Hi all. I started tracking my opk yesterday (CD 10). Im using easy@home tests and app to take photos of the stick. Yesterday I took my first opk and the app took the photo and it said “high LH 13” then I took another today and it said “high LH 21”

My question is, am I tracking toward ovulation? The test line is not darker than the control line yet....but I guess the “high” reading and number next to it is throwing me off.

What does the number next to the high even mean? Can I be “high” for a few days prior to hitting the “peak”?

Thank you!!!!