Is it normal

I am 7 weeks 2 days pregnant and this morning I decided to test with fmu because ever since getting my bfp at 8 dpo I have yet to get a hpt where the test line is as dark as the control line. I know that doesn't matter but I knew seeing it would calm my anxiety. Well my test line this morning was much lighter than it was 2 weeks ago. My symptoms have died off the last 2 days (I didn't have many to begin with) but I am worried to say the least. Has this happened to anyone else?