Am I crazy or is there a super faint line???

I don’t see it but I got a false negative with this test at 10dpo

I don’t know if I trust the light behind method. There’s plastic lines on the back and I wonder if that’s what you end up seeing.

I agree with not trusting the light method. I'd try placing it in a neutral light area (no shadows or extreme light) and check it there if it were me. I don't really like the first response tests. I got repeated negative tests all the way up until 19 dpo before I tried a different brand.

There’s a line behind the test. When there’s a light under the test, the shadow of it almost mimics the positive line.