Line Isn’t getting darker?

Be

My period is due on the 17th or 18th. I am normally a 9dpo tester(that is when I get all of my bfps) and the line gets darker each day, honestly. it has been a while since I’ve had a pregnancy, but these lines don’t appear to be getting any darker. I must admit, I’m freaking out just a tad bit. Thoughts?