I had unprotected oral sex with a guy about two weeks ago, and the day immediately after i had a sore throat, does this mean i have an sti?

Romance throat: If resolved quickly, throat symptoms may simply be traumatic (ie a bruising) due to forceful contact during the oral activity. That's often the case. An ulcer should arouse suspicion of infectious causes. In that case a virus, including herpes, or a bacteria, including syphilis, must be considered. There is treatment for bacterial disease, not so for herpes at this time.