OPK Question

Good morning!

It’s our first month TTC, and I’ve been trying to be diligent in charting symptoms, bbt etc. According to the app, I’m supposed to ovulate in three days, but the opk tests I’ve taken in the last four days leading up have been fairly-light to mid- light negatives. Should I be seeing darker lines as I get close to ovulation? Or is it truly a SURGE?

Also, how often should I be takin an opk at this point in my cycle? Every other day? Every day? Twice a day?

I’m trying to learn everything I can. Thanks for your input!