Recurring lower back problems, should I go see a doctor?

[Brandy]

I am 19 years old and have been having chronic lower back pain for four years now. In my sophomore year of high school, I hurt my back while playing tennis (although I'm not sure exactly what I did to it then but was out of tennis for a month) and the pain has bugged me ever since. I constantly am suffering from lower back pain and it has gotten to the point where I can't even do the things I love anymore like tennis. It hurts just to serve the ball. I can't even do regular push-ups anymore because of the extreme pain in my back. The pain comes and goes however when it is there it can be anywhere from moderately painful to severe. I also have several knots in my lower back that are constantly there and won't go away even with massages. My family thinks it is a herniated disc but I was wondering if it might be spondylolisthesis? Back problems run in my family and I know my father suffered from them as a teen. Do you think I should go see a doctor? Or what do you think I have? Any help would be greatly appreciated. Thank you.