Many people believe that a present and intact hymen signals virginity, but a torn or missing hymen does not necessarily mean the woman is not a virgin. A gynecologist can perform a test to ensure the hymen is present and intact, but they cannot determine without a doubt if the female is a virgin or not.
There are a small number of women born without a hymen, meaning there is no way to determine if they have had vaginal intercourse. There are also various ways that a hymen can become torn or broken. Strenuous exercise, excessive stretching, horseback riding, injury and even a pelvic exam can cause a tear in the hymen despite the woman still being a virgin.
On the flip side, just because a woman has her hymen intact does not mean she is a virgin. Sometimes women do not experience a tear in their hymen during their first instance of sexual intercourse, meaning they are not virgins but can pass a hymen examination.
Hymen reconstruction surgery can be performed by a doctor that is undetectable even by another doctor afterward. There are also products on the market that release fake blood during penetration to simulate the hymen being broken, but these products cannot fool a doctor.