Could I Be experiencing implantation bleeding?

Could this be implantation bleeding? My last period was November 17. My calendar said I was fertile through November 28 to December 8. And ovulation day was December 3rd. I had sex on the 27, 28, 5, and 6. I am to receive my period on the 17th of December. Well, on the 13th I spotted once, then on the 14 I spotted that morning. Well, that night I could wipe and there was blood (dark blood). So, I thought I was getting my period. So, I put on a pad, and whether to bed, woke up this morning and their wasn't enough to fill the pad. But when I wiped there was still blood ( mixture of dark and light red). Could it be my period or implantation bleeding??