Vaginal odors can be cause by bacteria/yeast infection. Do you have discharge? I suggest you see your Gyno. Make sure you get a pap once a year.
It could be Bacterial vaginosis (BV) is the smell there all the time or just when you have sex? because having sex when you have BV can make the odour a lot worse.
Odors can be caused by bacteria and other infections. Are you have any other sympoths..Discharge of any kind? I would say to see you GYN so they can do a culture and see if anything grows. Then they will be able to treat you. Best of luck!