It's a really short period of time for a STD to show any symptoms to be honest. But if you performed oral sex on a man, you should know that you exposed yourself to several STDs. You can test as it follows:
-3 weeks after the exposure, you can test for gonorrhea.
-6 weeks after the exposure, you can test for syphilis, and if you get it negative, you can repeat it 3 months after the encounter, as there are people that take longer to show a positive result.
-3 months after the encounter, you can test for herpes.
All the best.