Is this normal?

Does this look like normal line progression? Top test is from 12/20. Then to the 21st AM, 22nd AM, 22nd PM, 23rd AM, 24th AM, 24th PM (unlabeled) and then the bottom one is today (12/25). According to my LMP I’m only around 4w4d, but I just wonder if the lines should be getting darker? I’m also not having very many symptoms… like sometimes I feel nauseous or my boobs hurt but it comes and goes randomly and is not constant/consistent at all. Should the lines be getting darker by now? Does this line progression look ok?

I’ve suffered a lot of chemical pregnancies in the past so I am petrified. Praying for a healthy, sticky baby!!!