Hi thanks for your question.
You had unprotected sex on the first day after your bleeding stopped, then you took plan B
.There was no need to take plan B as this sexual exposure as at was your safe period. The abdominal pain
, spotting and headache these all are side effects of plan B.There is nothing to worry. These side effects will disappear within one week however spotting may remain persistent. You cannot conceive from next unprotected sex as you are bleeding due to side effects of plan B. You should consider some regular method of contraception
as Emergency contraception is for emergency purpose only and not a substitute to regular contraception.
hope this answers your question.