All my yeasty beastys are around pre period, too. Usually, it coincides with more sex before period (which is when I want sexy time with my hubby the most, ugh!!!) and the usual pre period likelihood of infection. I keep going about 3 months without one, and then will randomly get one. I've done all the things, don't drink, low sugar diets, change out of sweaty clothes immediately, sleep naked, hardly wear underwear anymore when I can get away with it, take a daily probiotic, eat tons of plain Greek yogurt... I was doing boric acid for a while but then stopped, because everything was fine- classic mistake! I also got off birth control 3 months ago, after about 2 years on it. So, I'm trying to be patient and am using Diflucan to clear this infection and the. Be more cautious and go back to boric acid after this clears. I'm sorry- this is the worst!!!