Practiced oral sex years ago and HBV

Patient: Dear doc, I am a male, 20 years of age. When i was 16 I had my first and last sexual relation (only oral sex) with a girl. I am certain that she doesn’t have any sexual partner before me at that time,i am also her first, and she doesn’t have any contagious illness. I am now sexually inactive for about 4 years due to my new religious beliefs. I see nothing wrong about my health for the past years upto now. But, lately i was disturbed by the thought that I may be infected, specially with Hepatitis B. Do I need to be anxious about it? Am I at risk of having HBV because of giving and receiving oral sex 4 years ago? Your response will greatly appreciated!