Do I have an STI??????

Go to your GP and get tested, Im a 16 year old male and when I was 15, I thought I caught a STI so I went to the GP and I got tested and was all clear end of story. He asked for my age, I planned on lying but hesitated and said I was 15, he asked me did I use protection and did my parent(s) or guardian know that I was sexually active under age, I said no. I also asked if possible that they would not find out about this ordeal , he said that's entirely up to you.