Hi Sean
You can relax.
Your partners assessment is very sensible and I believe correct.
The condom was intact throughout and he did not ejaculate into the condom whilst inside you. He is on antiretrovirals and his HIV is well controlled with an undetectable viral load. The evidence available - which is good and increasing - supports his statements that there is no risk in the circumstance you have described.
You can get more information by reading this article by Hunter Handsfield and Edward Hook
http://www.medhelp.org/aids-hiv/articles/Anti-HIV-Treatment-Markedly-Reduces-Sexual-Transmission/195
I do not think you have ARS and PEP is designed to suppress viral replication and so will halt ARS for the duration of treatment. Occasionally we use antiretrovirals to suppress ARS symptoms where people are very unwell ad they work well.
PEP can fail - but in your case you have a partner who is careful; well controlled disease and condom protected sex. You had a sexual event with an HIV positive person but you did not have an exposure.
If you had attended our clinic then we would have done our best to disuade you from taking PEP as it is not necessary.
You are fine. Truly.
best wishes, Sean