Several things happen during a pelvic examination.
First, the doctor is going to look at the vulva, major labia and minor labia. If the patient has a sexually transmitted disease with active symptoms, those symptoms often show up here. Sores from herpes, gonorrhea, and syphillis, as well as genital warts, will be apparent. However, a lack of these does not indicate there is no disease.
The doctor will check to see if there is any redness, tenderness, or swelling that might indicate an infection or trauma. Even relaxed, happy sex can cause some trauma to the vagina - small tears or bruises. Significant trauma, especially considering circumstances of the patient, can indicate sexual assault or early sexual activity.
The hymen, a membrane stretched across the mouth of the vagina, is often taken as an assurance that the patient has not had penetrative vaginal sex. However, this is not necessarily true. The hymen can stretch or partially tear, allowing penetration, without being completely destroyed. If the hymen is present and intact, then the doctor will check for any possible complications, like an occlusion that might prevent menstruation. This is very rare.
Next, the doctor usually palpates the pelvic organs by placing one or more fingers in the vagina and her other hand above the pelvic bone. She will check placement and size of the uterus and ovaries. Palpation can be uncomfortable, but an unusually guarded or painful reaction from the patient can indicate cysts, infection, or other complications.
Using the speculum, the doctor will then inspect the walls of the vagina and the cervix. Again, there may be signs of a sexually transmitted disease, such as lesions or warts, or trauma such as abrasions or tearing. The doctor can spray a dilute solution of acetic acid (vinegar) into the vagina, and any genital warts become prominent. White, grey, yellow, or green secretions, especially if there is an unpleasant smell, indicate bacterial vaginosis.
The cervix - the opening of the uterus into the vagina - can give a great deal of information. During ovulation, it softens and opens very slightly and usually has a specific type of mucus that aids semen transport. If the woman has had part of her cervix removed due to pre-cancerous tissue or cervical cancer, there will be scarring present. If she has cervical cancer, and it has progress beyond Stage I, it may be visible as a lesion or tumor on the cervix.
The opening of the cervix in women who’ve never given vaginal birth appears as a pinpoint. In women who’ve given vaginal birth, it appears more as a flattened dash. A pregnant woman with an incompetent cervix may have several sutures taken to keep the cervix closed while she carries her child.
That’s about all a doctor can tell by a visual inspection. Diagnosis of any lesions or other tissue must be done by smear, staining, and microscopy. A Pap smear is necessary for the diagnosis of cervical cell changes that indicate cervical cancer.
A doctor cannot tell during a pelvic exam if the patient has ever had an abortion, if they have a sexually transmitted disease, if the patient has ever been pregnant or had a miscarriage, or if the patient has ever had penetrative vaginal intercourse. While some things may indicate one thing or another, there is no certainty.