It is is fishy it could be BV, which requires antibiotics. If it is more sour, it is probably yeast. There are creams over the counter or a pill by Rx for that. See your gynecologist. If you are having sex, you have to see a gynecologist and get checkups.
It could just be a chemical imbalance down there. Unsure what its called again. But I got it alot as a teenager. Its quite common. Hp gave me mitronidazole which is commonly used for infections Xx