Thanks for the input. I had scheduled an appt. with an orthopedic surgeon, but it go so bad my daughter couldn't even walk to the bathroom. The swelling progressed and she developed a fever. I took her to the emergency room. It turned out it was a pilonidal cyst, and they lanced it. It will take several weeks of having the wound packed everyday, until it finally closes. Once she had the surgery, she was feeling a bit better within a couple of days. In 2 days, it will be 2 weeks since the surgery, she is better, but still is sore. She can't lie on her back and has to sit gingerly, but it's better than before.
Sorry I got sidetracked with telling my daughter's story.
I would take her to an Orthopedic doctor or an Orthopedic Surgeon. They'll take X-rays and come up with a treatment plan for her. If she goes to a regular doctor like a General Practitioner, they may order X-rays (and she may have to go somewhere else to have them done) and if there's something they think needs further evaluation, they're going to send her to Orthopedics anyway. Most Orthopedic doctors have X-ray capabilities in their office. Might as well cut out the middle man and the extra expense.
A couple of years ago, my daughter complained of her tailbone hurting her. She didn't recall falling, hurting herself, or doing anything that might have caused her pain. I took her to an Orthopedic Surgeon. He took X-rays and found she had broken it! The tailbone should curve towards the body. My daughter broke her's at a 90 degree angle to the spine. It looked like someone just took it from where it was attached and pushed it straight up. They said there was really nothing they could do because they wouldn't advise her to have surgery for correction. I'm concerned because what does this mean when she gets pregnant and goes through labor?