cd 27 but only 9dpo. why is my period starting!?

My periods range from 24 days-44days but those are the extremes. It is normally 32 days. I got a solid smiley on a digital opk 10days ago. Today (tmi 🚨) I got some brown color when I wiped after I went to the bathroom. I also been having a pinching feeling in my left lower abdomen near my ovary. I took a test this morning with second urine and I couldn't really see a line. Is this definitely my period coming or could it be implantation?