If i had unprotected sex and 3 days later i have a sore throat, thats all, something tike strept, is that a possible sign of hiv?

Probably Not HIV: Hiv like other viral infections has an incubation period. If you had a single high risk encounter 3 days ago you would not have signs of HIV now. Acute HIV infection may occur 2-4 weeks following exposure and is usually associated with other symptoms. There are many pathogens (both viral and bacterial) that can cause a sore throat (pharyngitis).

Not likely: Flu like illness due to acute HIV infection usually takes a few weeks. Please consult your doctor for testing for HIV and other diseases, e.g., gonorrhea that is more consistent with acute sore throat three days after unprotected sex.