If it is BV, as fourpaws suggested, you do need to go to a doctor and get a round of antibiotics. It is pretty common to get bacterial vaginosis, so don't be embarassed. But do go get checked, as it can turn into pelvic inflammatory disease, and that is more serious -- can cause inflammation in your tubes and block them.
It sounds like bacterial vaginosis. It's just when your body produces too much bacteria, kind of like a yeast infection, how you produce too much yeast, you get an infection.