Implantation bleeding or period

Hi ladies, i had sex on February 2nd, he didn’t come in me.. but i still took plan B because I realized i was ovulating. Two weeks after which was around February 12-14 i felt nauseous (which in my opinion super early to have pregnancy symptoms right) i was thinking it was due to the pill.

i was supposed to start my period today, but yesterday i started spotting pinkish brown discharge, which at first I thought it was my period. But the thing is it has stayed just super light looks nothing like my period. Could it be implantation bleeding?