Implantation bleeding?

So i had unprotected sex on the 31st going into the 1st in the afternoon on the first i thought i started my period, a normal period for me is very heavy and this one isn’t.

Started dark and it’s gotten red but this period is very light period mild cramps and mind you my cramps are normally awful now on the 5th my period is done and my periods last a week plus normally today i feel sick as well nausea but not throwing up