Thoughts?

Okay so I got my first BFP on the 24th of Feb. My lines continually got darker all the way through March 3rd with a really dark line. Then yesterday & today I got very faint lines! Is that weird? I thought I had passed the point of possibility for a chemical pregnancy. I also have been drinking more water/electrolyte drinks the last two days which also makes me have to pee a lot. Am I overthinking or should I call the doc? I’m 5weeks 5days