You say that your partner describes a “sour” taste during oral sex. You don’t have a discharge, shower before intimacy, and wonder if you could have an infection and not realize it.
The vagina has its own environment called the vaginal microbiome or vaginal flora. Multiple species of bacteria reside and belong there, a lot like the gastrointestinal tract. Over 300 species have been discovered that can reside in vaginas, and the specifics of that microbiome vary from one woman to another: We don’t all have the same composition of bacteria species.
One feature is we all share is a dominance of lactobacillus, which is “good” bacteria that helps keep the pH in balance (acidic is good), and prevents the “bad” bacteria from overgrowing and causing infection.
You cannot sterilize your vagina, of course, and we recommend not douching, either; this tends to disrupt the delicate balance that nature has worked to achieve and puts you at risk for infection. The make-up of the different bacteria influence odor and taste. There will be a (usually) mild odor to the vagina, and the taste varies as well.
This is not a factor of being clean!!! The vagina is amazingly low maintenance and the less you fuss with it, the better. If you have an infection, you will have, as you note, symptoms of an increase in discharge, irritation, and maybe itching. This doesn’t sound like an infection: it sounds like Mother Nature at work.
Dr. Barb DePree, M.D., has been a gynecologist and women’s health provider for almost 30 years and a menopause care specialist for the past ten.