Everyone is different. Depends on so many things, how high your natural level of hcg is, how soon you implant, how sensitive your test is and so on. I had a faint positive on a cheapie (one step and cassanovum brands) at 13dpo, the same day as I had one on a frer. I'd had negatives at 12dpo. I have naturally low hcg so it take it a while to rise to a detectable level, I've never had a positive sooner.
