Advice please

Khrys

So my period was aug 21-27. Had sex during my ovulation week, missed a day on accident. Just got a tracker tonight. Had light pink spotting that turned brown towards the end of the day Saturday(September 12) and now nothing. Not due for a period until the 17th..what could it be besides possible implantation. Lol I have three kids so my mind went straight there. Lol