Ladies I’m new to this and really need help please

Lexi

So I did the test analyzer on here and got my positive yesterday morning and yesterday night I took another one and it was much much lighter and I took another this morning just out of curiosity and it is dark again. Not quite positive but dark again. What made it dark again? Could this be an early sign of pregnancy? Please help, this is the first month using ovulation tests. These are all my tests together...

7/11 am

7/11 pm

7/12 am