Implantation bleeding

So 5 days prior to my period I began spotting very light pinky brown. I’m now on the 3rd day of spotting. This is pretty odd for me as I might have some spotting the day before my period but nothing so far out. My SO and I have sex only using pullout method as protection (since we’d be down for a kid but not directly trying). I took an first response test but it was a negative. What do you guys think? Just trying to figure out what’s up☺️