Having just recently suffered from the crotch fire myself, I can tell you from experience that if you guess wrong (yeast vs. bacteria) and treat it yourself, you can make it much much worse because then you've killed off the competing organisms. My guess is you have bv and you'll need to go to the doctor and get antibiotics. Continue with the probiotics so you don't throw it the other direction and develop a yeast infection after the antibiotics, which is what I did :P I just ordered myself cloth pantiliners after years of denial that my body just doesn't like the disposable ones. And yes, having an iud can make you more susceptible to vaginal infections of this sort. I still think it's the best non-hormonal option for bc out there though if you aren't ready to go the route of a more permanent solution.