Period or Implantation?

My period is a few days late but I think that’s because of the stress from school and family (?) I had unprotected sex nov 2nd which was 7 dpo. I had my period 5 days Later (nov 8 & lasted 4 days (normal)) after that I was due for my period this last Sunday (dec 9). I have been having some cramps for the past couple of days. I started having this tonight, could it be the start of a period or is it implantation bleeding?