You should not be concerned the chances of infection during a one time encounter are quite low I would not worry or test unless you develop urinal symptoms or blister/sores
Oral sex exposes you to gonorrhea, herpes and syphilis, but those symptoms are not typical from any of them. They could be due to any other reason.
The general risk is really low, but if you still concern, you can test as follows:
-3 weeks after the encounter, for gonorrhea.
-6 weeks after the encounter, for syphilis, and if the result is negative, repeat the test again 3 months after the encounter, as there are people that take longer to show a positive result.
-3 months after the encounter, for herpes.
All the best.