Thanks for your question. You need not worry as this a case of bacterial vaginosis which is common in women. Causes for this physical disorder may be the cause of multiple bacterial infection causing secretion of lactobacilli within the vagina which produces Hydrogen Peroxide, leading to excess watery discharge associated with fishy odor. Another cause may be due to your new sexual partner or due to use of intrauterine contraceptive device. Other causes may be due to smoking, antibiotics recently taken or vaginal douching which is cleaning of the vagina with water or fluids containing baking soda and vinegar. Consult a Gynecologist to have an opinion before you start any treatment. There is no reason to worry.