isn't the line supposed to get darker???

Brittney

I've taken some tests and there is definitely a 2nd line on all 3 of them. I'm not very good at taking pics, but they each have the slightest bit of pink. the Issue is, I've taken the top pic first, the second pic the day after, and the bottom pic is from just now (2 days after 2nd test). isn't the second line supposed to get darker? the top 2 are FMU but the bottom one is not. AF due today.