implantation bleeding?

10 days after ovulation, which is the day we had sex and the day before he did ejaculate in me I was ovulating the day we had sex and the days before I was fertile. I did take a plan b pill but ended up throwing it up 20 minutes after. Anyways I went to the bathroom a few minutes wiped and it was pink "blood", i wiped again a few minutes later and it was pink "blood" again. I've been cramping on and off today, Could this be implantation bleeding? My period is expecting either the 12th or 17th of this month.