Hi, I had gone through your question and understand your concerns.
You didn't mentioned your age, gender,any medical history,exactly the location of the pain?
As per your information,there could be many possibilities.
Knee osteoarthritis,
patella femoral problems, illiotibial Band syndrome,meniscal tear,
tendinitis etc.have few or more same symptoms.
To ease the pain before a doctor's visit, elevate and ice the leg, which can reduce inflammation and pain.RICE method will help--rest, ice, compression and elevation will help. Also stretches, strengthening exercises will help a lot. you can also take
physiotherapy sessions.Information provided by you is not enough.
Therefore,i will recommend you to see an orthopedician or a physical therapist.
Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us and voting. I will be happy to answer your questions.