Name changed for this as I'm sure I'll get flamed!
So many times on the conception board you see the following:
OP tests at ~10dpo and gets a very faint line, and posts a picture for others to look at. Posters confirm they can see it too and congratulate the OP.
A day or two later the OP posts again that they'd done another test and it was fainter, or negative. They are confused and upset.
A couple of days after that they get their AF. They are naturally devastated and disappointed.
If instead they had waited to test, they would just have got their period at about the expected time, and would have only had the disappointment of not conceiving that month (which I am not downplaying!)
What is gained by testing early? If the pregnancy is successful you will have found out a few days earlier than you would otherwise (on a 40 week pregnancy!). If not successful, you open yourself up to heartbreak of a miscarriage and dashed hope that you could have avoided by waiting until you miss your period until you test.
I'm not criticising anyone, especially not people struggling with infertility who are desperate to be pregnant. But I think that testing early, or using an early response test, is likely to cause more unhappiness and negates the benefit of testing early.
Do others agree or AIBU?