I had a problem with monthly vaginal infections. I was treated but they returned the following month. I was rid of them for almost 2 years, but I've been getting yeast infections now every 3-4 weeks. I've used Diflucan, Monistat, and Nystatin, and although I do feel relief, the infection seems to return. I've been tested for diabetes and HIV and both were negative. The oddest thing is that the infections seem to occur within days of receiving oral sex. Any link between these things or not?