TTC & YEAST INFECTIONS

Ever since my husband and I have started TTC I KEEP getting yeast infections. Is it too much sex that is causing this or is it something more serious? Has this happened to anyone else!? Since I have been TTC I have been eating a yogurt EVERY single morning to try to help with my yeast infections. Obviously it's hurting my chances because we can't have sex while I have a yeast infection. I don't want to infect him also. We want a baby so bad but this is seriously slowing us down!