Your symptoms are not ARS related..........it would appear you have caught a cold. Your PrEP regime will help you avoid infection, which is why you're taking it. If your partner was telling the truth about also being on PrEP, then chances go even lower. Testing for any unprotected sex is a given, but especially unprotected anal. While PrEP has a high efficacy rate, infection does still happen, even if it's rare. It's better to be safe than sorry, so it's good that you plan to test.
I wish you the best.