I understand what you dare saying, however had it went unnoticed, is the DUO test at 4 weeks conclusive?
I am having some symptoms that I can't explain. Do I need to test again at 3 months?
I understand what you are say
If the condom had failed in a way that would have put you at risk (I.e. your penis head was no longer covered) I believe you would have known it. Otherwise protected sex is a no risk situation. Of course, all your tests would be negative.
No further testing is warranted. You can move on.