yeast infection? discharge

I have had alot of vaginal disharge for a long time and i find it quite embarrassing. Its usually white and slippery but sometimes is yellow and can stain. There is also a slight odor but its not fishy. These are the only symptoms i have. Should i treat myself for a yeast infection with something over the counter or can this cause harm if you dont actually have a yeast infection? Does anyone know anyways to get rid of this? thanks for any replies