I am a 20 year old female with no previous pregnancies. I had intercourse this past Wednesday night and only used spermicide. I realized the next day that I was having symptoms of ovulation and decided to get plan b as soon as possible. I have taken plan b once before on the day after intercourse and had a regular period that month. I was on my way to the pharmacy today and stopped somewhere to use the restroom and noticed that I was spotting lightly. It was a small amount of pinkish blood and am not sure if this is spotting from ovulation or if implantation bleeding can occur this soon after the encounter. I still plan on getting the plan b in an hour or so when I have transportation but I was wondering if I should be worried about implantation already having occurred and if plan b will be effective or not.