Hello,
Thank you so much for your post and welcome to our forum.
By having performed oral sex with ejaculation in the mouth, you have put yourself at risk mainly of throat Chlamydia and/or Gonorrhoea, as well as a possible risk of syphilis. Other that that, there is a possibility of herpes if the other guy had genital herpes, and from the poitn of view of HIV infection, the risk is extremely low, practically zero and it is more theoretical then real.
In summary, I believe that initially you ought to be tested for Chlamydia and Gonorrhea with a throat swab and you can do this anytime after one week of the encounter. Other that that, you coudl always have a blood test for syphilis after 4 weeks. At the same time, you coudl alwso have a HIV Duo test, mainly just for your peace of mind as I would not consider that you had really put yourself at risk.
Best wishes,
José
If you have lesions suspicious of or looking like herpes then we can take a PCR swab from the lesion and this will almost always correctly identify herpes and discriminate between herpes 1 and herpes 2.
If you don't have lesions then there are two possibilities:-
1) take blood and then repeat in 2 weeks - if you have a new infection the "titre" - the amount of virus in the sample will increase.
2) wait 12 weeks and then take a single sample. If you have antibodies to one or other then that indicates infection with one or other or both at some point in time. This does not allow us to tell when the infection occurred - simply whether you have ever had it.