Unprotected penetrative sex with a man changes the pH of your vagina because semen has a pH of between 7.1 and 8. During sex, the pH of your vagina rises in order to create a more alkaline environment to protect the sperm and encourage fertilization. This can also encourage the growth of certain bacteria.15 Jul 2020
How can someone mess up your pH balance?
Any of the following situations can change your vaginal pH level: Unprotected sex. Semen is alkaline, which can encourage growth of certain bacteria. Antibiotics.