I had protected sex condom with a person who i dot know their std status. i am worried about herpes. it has been 5 days no symptoms. ?

Herpes very unlikely: The likelihood of new genital herpes from any single sexual exposure, especially with a condom and a partner not known to have genital herpes, is under one chance in several thousand. I really see no need for worry. Of course see a doctor if symptoms like penile blisters, sores, etc, most likely on the upper penis not covered by the condom. If none by 10 days, you're home free.