A 24-year-old patient complains of vaginal discharge and burning with urination for 2 weeks. The symptoms persist despite having taken a course of over-the-counter yeast medication and drinking cranberry juice to treat what she suspects is a bladder infection. She was contacted yesterday by her new boyfriend because he had been told by his doctor that he tested positive for chlamydia. She uses oral contraceptives and does not use condoms. Her urinalysis and wet prep of vaginal secretions in the office are normal. There is a moderate amount of gray discharge at the cervical os and in the vagina. Are there any diagnostic studies that should be ordered on this patient? Why? List the primary diagnosis and at least two differential diagnoses for this patient. Explain your reasoning for each. Discuss your management plan for this patient, including patient education, referrals, and follow-ups.