Implantation Bleeding? (TMI)

Hey everyone! First time posting in here and just looking for some general advice. I ovulated on either the 2nd or 3rd January. I know this because of EWCM, OPK’s and also cramps and twinges I normally get. So I’m roughly 6DPO now.

Last night me and DP had sex and everything was fine until I realise when I went to the bathroom and I wiped there was brown discharge present. Very strange and never happened before! This is our first month TTC properly (like timing it etc) and I just want to know if it’s possible to experience IB as soon as 5DPO? Prior to this bleeding I’ve had some sharp stabbing pains but ones that only lasted about 2/3 seconds in where my uterus would be? and some cramps in my pelvic area on the right hand side which I feel like that was the ovary that I ovulated from... I’ve had leg ache too for the past couple of days!

It could be me overthinking it and just praying for our BFP who knows but the discharge was only noticed after sex and it was brown and like I say never happened before.

Thank you in advanced! :-)