You can test up to 14dpo with a first response early response, but it's more accurate later on around when your period is due.
It just depends on how soon it was implanted and how your body is producing hcg. I tested 10 dpo and I got a positive.
10 days with an accurate test and FMU. 14 days with a standard test.
I tested 10dpo and got a faint positive...Good luck!