help with these ovulation tests?

so here are my last 4 days of tests

day 1

day 2

day 3

day 4

I feel like the line today is lighter than yesterday. I've been testing at the same time every day in the evenings. Right now the goal is to figure out if I'm even ovulating. According to Glow, I should ovulate this Friday. Just trying to have all the answers before I go back to the doctor again in a couple weeks.

I'm not real used to using the ovulation tests. Is it a normal thing for the lines to stay the same color over several days? I'll add more as I take them, I have 6 more tests and want to see if my body is working right and around the estimated time it should be.

Please feel free to comment, give advice or thoughts, ask questions, etc.