The first indicators in women that they may have contracted an STD is through abnormal discharge, odor, or irritation of the vulva, vagina, or anus. While it is common for women to have different discharge depending on their cycle or health, any noticeable changes should be checked, especially if the discharge is greenish or yellowish. Irritation of the vulva or vagina may appear as itching, a rash, or blistering. It is common for pain to be experienced during intercourse or urination. If the STD has been spread through oral sex, the throat may be sore as well. Bleeding that is not normal or easily associated with a period coming from the vagina could be indicative of an STD as well.