is it possible to experience implantation bleeding 5 days after taking the emergency pill?

last Monday, during the last days of my period, i had unprotected sex, so the next day i took an emergency pill. 5 days later, on Sunday (today) i started bleeding a little, not enough to use a pantie liner and rarely i get this VERY soft cramp feeling in that area and also feeling kinda nausea and shakey. i remembered that i had took an emergency pill 2 or 3 week before and was wondering if this faint bleeding could be early signs of pregnancy, and if it is, how could i stop it...