Implantation bleeding at 12DPO

Alana

I had my O day on Feb 13th, have been testing negative the past few days. But have had crazy different symptoms this TWW. AF is supposed to start tomorrow. Yesterday I noticed so pink/brownish tint on my underwear. It hasn’t increased yet.

Has anyone had later implantation bleeding and how long after noticing it will you typically see a BFP?