Hello,

Thank you for asking your query at DoctorSpring.

It is very unlikely to be STD. Reason being it does not fit into the symptom pattern of STD, and oral sex has very low risk of STD transmission. NO ulcer / lesion , no Urinary symptoms etc almost rules out STD.

However the groin swellings ( ? Lymph Nodes) and the testicular pain needs evaluation. Lymphogranuloma venereum one possible infection that can cause lymph node enlargement like this.

As you have rightly said, you do need some test.
I recommend a Ultrasound Abdomen and testes, Basic STD screening and test for Chlamydia. Antibiotics with out testing will not be useful.

So to conclude - STD less likely. But the symptoms needs evaluation. If you can get the tests done, please get back to me with results. Alternatively you can consult your GP with results.

Hope this helps
Please feel free to ask followup questions.
Thank you

If the swelling was only for day , then it is less likely to be lymph node. So LGV is very less likely. Yea , I do not think it is STD. But a basic STD screening may be done if symptoms persists.

Thank you