Why are my cheapie tests still faint?

I found out I was pregnant at 10dpo with a very faint line on wondfo pregnancy strip test. The next day I used 1st response and the line is clearly dark (picture below):

At 13dpo, I used digital test:

And today at 14dpo, I used wondfo test again, and the line is still faint, it’s darker than before but not dark.

Is this something I should worry about? We’ve been trying for 2 years, 1 mc, we pray a lot for this one to be healthy. Our insurance will not work till Jan 1st.