I have had something like that and it went away by itself. It was called a Gartner's duct cyst. It felt like the left side of my inside vagina was swollen, but no pain or itching, and it was very close to the outside. Some sensitivity when I touched it, but I could forget about it so it wasn't severe pain. This duct is active during fetal development but ordinarily disappears after birth. In some cases, however, portions of the duct may collect fluid and develop into a vaginal wall cyst later in life. Mine was not a hard cyst, just a swollen area for a few days and it went down by itself. Since it is inside there is very little you can do to bring down swelling, except take ibuprofen. The only treatment needed may simply involve routine exams and watching the cyst or swollen area for growth and other changes. If you have pain or itching as well it might be an infection. If it was very rapid onset then it could be trauma, from something as silly as sitting on a bike saddle too long. I would wait it out tonight since it is Sunday but if it still bothers you in a day or so, then try to call you doctor. I know you are between insurance, but I call my doctor's office much more often than I see them. You can just call the nurse line (or the option 'seeking care today or advice' depending on how they put it) and state you are so-and-so's patient and have a question to decide if you need to come in. I would urge you to continue pap smears and such even without insurance. Good luck.