Bacterial Vaginosis. Sometimes disturbances to the natural bacteria in your vagina (douching, irregular bleeding, unprotected sex, etc) can allow abnl bacteria like Gardnerella to overgrow and cause a fishy odor. It's not sexually transmitted, but can be treated w/ Metronidazole (Flagyl)/Clindamycin/Boric Acid. See your GYN for a prescription and be examined for other potential causes. Nothing urgent/dangerous though.
No connection. There is no connection between what you eat and odors from the vagina. Have a gynecologist examine you to check for any abnormalities. It's quite possibly normal secretions with natural odor that you're experiencing.