Implantation bleeding

Sa

I know implantation bleeding is not that common and you can’t be for sure that’s what it is (IB warriors no need to come for me) BUT those who think they had it how long before you tested positive? I’ve been spotting brown for four days now. Not even enough to touch a pad, just when I wipe. I haven’t tested yet because I just assumed it was my period coming but I’m starting to maybe think it’s not?