Can anyone tell me about implantation bleeding - what it looks like, how long it lasts, how long after experiencing it you would be able to get a +ve hpt?

I woke up yesterday (DPO9) to find a pink tinge when i wiped first thing in the morning. Last night, following BDing I experienced some brown discharge. My first thought was that this must be implantation bleeding. Then this morning I woke up to again find the pink tinge when I wiped. Much more prominent than yesterday but still not what I would classify AF, although this is my first mth off the BCP so it could be my first AF appearing super light!? On and off all day today I have experiencing pink - brown tinges upon wiping and some barely there spotting. I am only having to use panty liners. I don't want to get my hopes up and as this is my first time ttc I really have no idea what to expect! Hoping some of you can offer some advice.