If you are experiencing pain in your vagina, lower abdomen, and severe back pain at 39 weeks and 6 days pregnant, it could be a sign of labor. It is important to listen to your body and seek medical advice if you are unsure. Contact your healthcare provider or go to the hospital for an evaluation. They will be able to assess your symptoms and determine if it is necessary for you to be admitted or if there are any concerns that need immediate attention. It's always better to err on the side of caution when it comes to pregnancy-related discomforts.