Bfps are not getting darker

I don't really know what to do.. I can't go to the doctors because of work :/ 
 I'm cd29, 13dpo and AF is due tomorrow.. I've been testing since 7dpo and since 8/9dpo I have been getting faint lines on all brands of tests.. I've tried as many different brands possible.. And all faint lines..
​Well, I'm 13dpo today, and was expecting yesterday's faint line on a casette test to get darker today, but I just tested with fmu and it's there but I don't think it's any darker.. Any suggestions as to what's going on? 

Glow Resources

Let’s Glow

Glow is here for you on your path to pregnancy

Glow helps you navigate your fertility journey with smart tools, personalized insights, and guidance from medical experts who understand what matters most.

25+ million

Users

4.8 stars

200k+ app ratings

20+

Medical advisors