Retested and line is still faint

RM

I should be about 5 weeks exactly today, and I just retested with a ClearBlue test and the line is still just as faint as it was two days ago. Should I be worried? I hate these ClearBlue tests!! Always messing with my mind!! Should it be much darker by now? Or is this normal? The first pic is today and the second is from two days ago.