HELP. Potential Chemical pregnancy?

Ladies, my hubby and I have been trying for 2 years. We’ve just had a round of ivf. We got 1 egg. 1 embryo. 1 chance. I tested Saturday because I just knew (I’ve already got 2 kiddies) I was 8dp2dt (the equivalent of 10dpo) and it was the faintest positive!! I then tested yesterday and today using the same tests and FMU. The tests appear darker as the days progress (within the time frame) and it’s clear to see BUT the 9dp2dt (11dpo, yesterday) dried darker than today’s and now I’m down a spiral of a chemical. I know hCG doubles every 48 hours so the difference between 8dp2dt and 10dp2dt (10dpo - 12dpo) is good. What’s your thoughts? Potential chemical? I’m going to test tomorrow to compare yesterday’s. Also, any experience with clear & simple tests for progression? Thanks ☺️