Spotting a week after taking plan b pill. should i be worried?

Spotting after PlanB: Could be several things, but first, get a pregnancy test. If its negative, thre's likley very little to worry about, its just the rest of the lining being shed.

May be a side effect: Potential side effects w emergency contraception includes menstrual flow changes (spotting, bleeding, early or late period), nausea, vomiting, dizziness, fatigue, headache, breast tenderness & abdominal pain or cramps. Take pregnancy test & notify dr if your period is 7 or > days late.