OPK help!! 🤔 (Newbie here)!!

So! I got an opk box of 20 tests today. Equate Brand (Wal-Mart). I have never used them before so I'm not 100% sure how the test line works. I know the basic. If the test line is AS dark as or DARKER than the control line, that's a positive.

I use 3 charting apps for comparison (and just for fun). Glow, Fertility Friend and My Tracker- pink with a flower.

All 3 apps show a different Ovulation day, My Tracker- shows tomorrow, Glow shows the 1st, and Fertility Friend shows the 2nd. These are based on their own algorithms.

Today at 10 a.m. I took my first opk and waited for the line to show up. I did get a test line but a faint one. So I used Glow's opk analyzer to tell me negative or positive. It said negative.

My question is, since I am in my fertile window, how many times a day should or do you ladies test with opk's? Once in the a.m., one time a day? At night? Twice a day? Etc.

I am also curious if a woman does not ovulate during her cycle,would a test line show up? Or would it be blank?

And lastly, I am uploading a pic of my opk. How close do you think I am to Ovulation? Should we start BD now? Or wait until the test line is darker?

Thanks in advance!!