What does this mean?

I've been taking the ovulation test for quite some time, but the last 3 days 16-18 of this month I've taken ovulation test and they all have shown around the same color. YES I KNOW THERE NEGATIVE SO DON'T EVEN SAY A WORK ABOUT IT. Some of the test were taken at same times and some at different. My question is why am I getting sorta same results for 3 days in a row.

10~16~18: the first two test was taken in the early afternoon and late afternoon. The 3rd test was taken 9:02 pm.

10~17~18: these 2 test were taken at the same time.

10~18~18: same with the last 4 test. All taken with same urine.

I was taking some at the same time to see if they showed totally different results!