plan b and spotting

so i took a plan b last tuesday which was the same day i have unprotected sex. he didn’t bust in me but it dripped and i just want to be safe. yesterday i noticed very very little spot of blood in my underwear and then this morning i saw just a little more but not much. and during my last cycle i took a plan b too and i know that’s not good for my body at all. so do you think me taking on last month and then this month is causing me too spot or is it implantation bleeding? i’m also not cramping, but i’m a little bloated.