What does pink brown discharge mean if you haven't had sexual in 3 days?

Baginal Discharge : Read this webmd article: http://women.Webmd.Com/guide/vaginal-discharge-whats-abnormal. At age 18, most of the serious diagnoses are very unlikely. Of course, you could be pregnant from a prior encounter, but a cervical polyp or infection could be in play. I would contact your gynecologist and explain your symptoms - he will likely have you come in for an evaluation.