My vagina smells and I have body odor why is this?

PH off/infection? Bacterial infections typically cause a bad odor. The bacterial infection could be an overgrowth that represents a change the pH and a change in the vaginal flora. It could also be from a sexually transmitted infection. Also, you should make sure that you didn't forget a tampon inside. See your doctor for the appropriate tests/cultures and treatment.
Has to do. It has to do with bacteria on your skin. Sometimes eating onions and garlic can cause it also.