"I am sure i had nothing more than described with the girl." I agree.
Therefore, I don't know why you are "very worried"!!!
Syphilis is not likely to cause a pimple anyway. However, herpes can do that -- although if you have genital herpes, you can safely assume you had it before the exposure mentioned above.
"What I have to do?" That's easy, and I think very obvious: visit a doctor or clinic.
I'll be happy to comment once again if you would like to return to let me know the results after you have been professionally evaluated.
Dear Doctor,
This evening I just noticed something very similar to a pimple on on the skin covering the penis, 0,2 0,3 mm. I am sure i had nothing more than described with the girl. What I have to do? I am very worried thanks
Welcome to the forum.
Neither syphilis nor any other STDs are transmitted by hand-genital contact or by exposure to saliva. You are not at risk.
Best wishes-- HHH, MD