Did you recently had unprotected sex?
Any lesion/ rash on genitalia?
Burning urination? fever? Age?
Since how many days you have these symptoms?
have you undergone any investigations?
As STD has been ruled out, so the possible causes are-Urethritis and Bladder Infections. As such urine microscopic and detailed examination , along with swab test from penis discharge will be done. So you should see doctor for evaluation and management.