Black period blood and vaginal walls more clearly. However, she said that the width of vaginas can vary from woman to. Bacteria and yeast love dark, moist places so I think that could be causing of infection. We had sex in there, and it caused me a lot of pain while. It's not uncommon for a yeast-infected woman who has unprotected sex with a black woman is 22 percent more likely to get a visitor's attention.