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If the discharge is not got controlled with the prescribed medication, then there could be a resistant infection, or infection caused by other agents (so the same medication might not work again). You should consider visiting your gynecologist for an examination and vaginal smear/swab test along with culture sensitivity to look for the exact causative agent. Get started on appropriate treatment as suggested by your test results. Avoid having intercourse while being on treatment. Get your partner also treated simultaneously to prevent chances of re-infection.
Take care.