"i had unprotected sex and took plan b less than 24 hours after. a week later, i began to bleed for three days and by the fourth it was a brownish color. im not sure if this was caused by the plan b or it&#039;s my period because i got my last period july 9th. i recently got very sick, sore throat, cough, back pains, tender breasts. i also threw up this morning. i have a doctors appointment tomorrow and will see if this was caused from the plan b."