Worried my line isn't getting darker. :/

Ash β€’ πŸ’•πŸ’™πŸ’™πŸ˜πŸ˜πŸ˜

According to glow I am 4 weeks and 1 day.. I have a short cycle, only about 23 days. Today I am 3 days passes my missed period and 15dpo. Should I be concerned that these lines aren't darker? The middle one was Wednesday and now 2 days later the line looks exactly the same. Shouldn't there be more progression? :/