Pain in testicals

Hi my name is Farooq.My problem is that some times i feel very bad pain in my testical and in vain which is going towards anus.I visited docters many times he told me that everthing is fine and he gave me pain killer name ciproxin and gave me a test of X-ray of my testicals when i show test results to docter he said everthing is fine.So i want to know if everthing is fine then why i feel pain in my testicals.One thing i wat to tell you that at the starting when ever i masturbate and i was near to discharge i hold my penus tightly or press part of the body behind the testical so that sperm dont come out of my penus so please help me i wat to get rid of this pain for ever.