During a transvaginal ultrasound, a probe is gently inserted into the vagina to capture images of the reproductive organs. The depth of insertion varies depending on factors such as gestational age and individual anatomy. Typically, the probe is inserted 2-3 inches into the vagina. The procedure may cause some discomfort or pressure, but it should not be painful. It's important to communicate any concerns or discomfort with your healthcare provider who can guide you through the process and ensure your comfort. Remember, this procedure is routine and performed by trained professionals to monitor your baby's development and ensure a healthy pregnancy.