so, for several years i suffered from chronic candida overgrowth. in that time i learned a lot about prevention and natural remedies, but i want to open by saying that i was not pregnant while pursuing these remedies so i would advise you to do your own research about pregnancy impact.
here's what didn't work for me:
-inserting a peeled clove of garlic vaginally, leave there for ~8 hours. this method also *seems* like it would be quite pregnancy safe.
my favorite natural remedy:
-apple cider vinegar sitz bath. pour 16oz of raw apple cider vinegar in a shallow bath and stay in the bath for at least 15 minutes. i also *think* that this would be totally pregnancy safe.
as for tea tree oil, it's my most used and quickest home remedy, but also the harshest. now that i know my body's candida reactions well enough to know when i'm approaching overgrowth, i dip a finger and diluted TTO and insert it vaginally. this is not the classiest way to apply, sure, but its fast and it works for me. I stopped using TTO this way when i began TTC though because TTO is quite harsh, as others have said (yes, it stings a little bit, it didnt bother me), and i was worried that it would interfere with my cervical mucous.