Hello dear user! Welcome to Healthcaremagic. I have gone through your query carefully and understood your concerns! Regarding to Depo-Provera, the contraceptive method you are using for birth control I would say that the most common side effect of it is spotting. Irregular menstrual cycle or absolute absence of periods may occur as long as you take that contraceptive shot. Abdominal cramps, weight gain, acne are some other side effects of it. The fishy smell you are having suggests an infection of your genital tract, called bacterial vaginosis. Trichomoniasis is another condition caused by trichomonas vaginalis (protozoa), which can be associated with fishy smell. You may feel itching, burning, or have vaginal discharge too. This condition requires an antibiotic cure to be removed. I would recommend you to go through a vaginal secretions analysis, and see a gynecologist to determine the type of the infection and adjust the proper treatment. I hope this answers your query. Please kindly write a review about this experience with me and click I find this answer helpful to allow me assist you better. Thank you and Best regards! DR ERIOL.