Hi there!

Ok I need help I am not sure what to do. This is my situation: I had unprotected sex on 1/1/12 at about 9:30am. I then took the morning after pill (which I regret now) at about 6:30pm on 1/1/12. I was supposed to get my period on 1/2/12 but I then began spotting very light on 1/4-1/7/12. On 1/08/12 I began bleeding a little heavier and lasted until mid day on 1/10/12. I have been taking prenatal vitamins since march of 2011. I took a home pregnancy test on 01/08/12 and it was negative.Is there any chance that the prenatal vitamins helped implantation BEFORE I took plan B? Is there any chances this was my period or is there still a chance I may be pregnant?

No I don't think the vitamins really did anything to effect your plan B pill. While not 100 percent, taken this soon after sex, it is fairly effective.

Next the plan B pill will effect your cycle for a couple months.

And no HPT will not show up anything yet it would be a couple more weeks before they would show pregnancy.
But I doubt you are at this point.