How to tell a guy I have thrush?

I’ve been seeing this guy and we haven’t been able to have sex yet because I was on my period and now that i’m off it I discovered I have thrush. We’re going on a drive later which I think he is hoping will end in us having sex but I obviously can’t. How do I tell him without him being turned off or disgusted? Is there a better way to phrase it than “I have thrush?”

help a girl out:(