It is always better to get tested for following STDs if you had any unprotected oral receiving encounter:
01- Gonorrhea (7 days later)
02- Syphilis (6 weeks later)
03- HSV 1&2 for herpes (there is no cure so better to get tested if you have an outbreak because 1 in 3 adults already have antibodies for HSV so it would be probably positive.)
04- Urinalysis for NGU (Non-Chlamydia) (7 days later)
There is no need of screening for Chlamydia as it is very rarely transmitted through unprotected oral sex. I won't recommend HPV testing because for male there are no specific tests and it is not curable.
Unprotected oral may cause hsv,syphills,hpv and other diseases.
For syphills wait atleast 3 weeks,
For hsv wait 3 months and
For hpv please consult doctor.
Thanks