Whenever I get my period I get a yeast infection?

I got my first yeast infection in November after sitting in a wetsuit all day after scuba diving. I treated it, but every month since then I've gotten a yeast infection at the start of my period. I can feel that I just got another one today. I'm worried this is going to happen for the rest of my life! And it also sucks that tomorrow is valentine's day and my boyfriend is coming to visit.

Has anyone else experienced anything similar, and if so what did you do?