Yeast infections after sex

I get yeast infections after sex but we use a condom and lube when it feels dry. Plus he doesn't have one. And i don't get one if i don't have sex. I've been to the gyn countless of times. I've changed few gynos and i still get them. I don't have std I've been tested i don't use soaps and i get them only after Sex..... What's the deal? I've tried probiotics, boric acid, i don't eat sugar.. I've tried everything. It's been on and off going for 2 years, usually once every 1-2months. I stopped going to the gyn and use the otc stuff and it works just the same as whatever doctors prescribed.. I've had a swab and pap smear and it always comes back positive on yeast. Sometimes i don't even have yeast and it comes back clear but i still get it again in a month.