Suggest Remedy For A Burning Sensation In The Penis

Hello. I am a 25 year old male. I recieved unprotected oral sex once from a new partner about two weeks ago. about 4-5 days later I started to feel a slight burning sensation in the tip of my penis. I does not burn when I urinate but it starts a few minutes later. I do not have any discharge. I have a girlfriend of over 3 years that I have unprotected sex with and I am concerned and worried. I dont want to pass anything onto her. I had sex with my girlfriend about a week and a half ago. I wonder if I should be worried, or if Im having symptoms because Im over thinking this?