Help - SO confused

Ok so, I got a positive pregnancy test on Monday, albeit light. I went to the doc that day to have my beta drawn and it was 16.3. Over the next two days, I swore it got a littttle darker - see below:

Tuesday fmu

Wednesday fmu

However, I went to the doc on Wednesday and my beta didn’t change AT ALL. So my doc was thinking it was a chemical, but said to come back on Friday to confirm. Fast forward to today. I took this test first thing in the am and was like yup, much fainter, definitely a chemical:

And then just for shits and giggles, I just took this test, clearly not fmu, and got the following:

WHY IS IT DARKER? Am I seeing things? Could this mean I’m actually still pregnant? So confused.....