12 dpo implantation bleeding?

So I’m currently 12 dpo and this morning I woke up with light cramps & a tiny bit of bleeding so my first thought was darn its AF & I wasn’t pregnant. However the cramps only lasted a few minutes and since 4 am I haven’t even had enough bleeding to fill a panty liner & its more brown than red which is very abnormal for me my first day is usually a scene from Carrie with tampon changes nearly every hour. Could this be implantation bleeding? I did feel nauseous the last two days and feel like I’m peeing more frequently but not sure if its just my mind playing tricks on me

Editing to add my period isn’t due until Saturday so its also 4 days earlier than expected which is another reason I don’t think its AF ever since & went off birth control last year I haven’t been a day off schedule