With what you describe, you do not need to test for HIV as that is not a risk for HIV. HIV is only transmitted in adults through unprotected vaginal or anal sex or sharing of IV drug needles. Both air and saliva inactivate the virus so oral sex when giving or receiving will not transmit HIV. So, NO worries there about HIV.
Other std's can be transmitted via oral sex. From someone giving you oral, they could pass on oral herpes to your genitals which is fairly uncommon but can happen. Other std's are also a possibility. IF (and it is a big IF) the person who performed oral sex on you had chlamydia (rare) or gonorrhea of the throat, they 'could' pass it to you when performing oral sex. HPV can pass orally but is also pretty uncommon. You could potentially also get syphilis from receiving oral sex but he risk is also low. See any sores? So, the risks are very low but you should still test.
Testing:
HIV-- unnecessary for oral sex
Herpes--- sores typically develop 4 to 10 days after exposure, symptoms could happen later. If you were to develop symptoms, testing at 3 months
Syphilis--- 1 to 3 months after exposure, can retest to be sure at 3-4 months for accuracy.
Gonorrhea-- can be tested relatively quickly after exposure but most accurate after 14 days
Chlamydia-- can be tested relatively quickly after exposure but most accurate after 2 to 3 weeks
HPV-- really not worth testing in my opinion.
Please note, that is just through my own reading and I am not an expert. But those are the time frames I've seen most. ****
And also remember, your risks were low. Hope that helps.
Oral sex exposes you to gonorrhea, syphilis and herpes. YOu should test as follows:
-Gonorrhea, three weeks after the exposure.
-Syphilis, 6 weeks after the exposure.
-Herpes, 3 months after the exposure.
All the best.