STI symptoms right after sex?

Me and my current partner had oral sex the night. It was our first time hooking up. Not even an hour after we had sex he says he was itchy and had a tingely feeling in his penis(no rash or discharge)He hasn't had sex in over a year and I was tested after my last partner and it was negative(routine testing) nor have any of my past partners been positive. He has a history of yeast infections and uti. The clinic says it too early to tell. Could it be an sti that quickly? I though that there was an incubation period?