I would agree that a positive 2 days after an encounter would not be due to that encounter, yes.
HSV experts are NOT fans of the inhibition assay, for sure. And now you see why. Those results are all over the place. That is just shameful. However, it is possible that given the additional time since the unprotected encounter that you had, you are now positive when earlier you were not. Please don’t waste your money on anything else but the blot. Clearly this is what you need (which you knew I would say). You are the poster child for needing the blot!
Have you asked the unprotected partner to be tested? If not, please do.
I think you are not likely infected but I’m not certain at all.