Ovulation test result changes within a few hours 🤔

So I took a few ovulation tests today, (about four hours a part). The one I took at 10 AM possibly could have been on the positive side, so I decided to test again at 2 PM, about four hours apart, and the tests now are clearly negative. Have you ladies experienced this in the past with ovulation tests where there is such a change in a matter of a few hours between tests? I’m just curious as I’m still learning how this whole process works! Thanks in advance!! 🙂💕💖 (ps the last picture are my ovulation tests the past four days 🙂)