Pink spotting cycle day 13??

Period 9/4-9/6. Had sex on 9/11(cycle day 8). Today is cycle day 13 and I’m spotting light pink. It’s light pink when wiping. Very crampy. Any suggestions on what this could be? Ovulation spotting? My best friend keep saying implantation spotting but I don’t believe that’s possible this early. I’ve been very nauseous, dizzy/light headed, with a major headache. I’ve been in bed the last two days because moving around too much makes me sick.