Yeast infection?

The last few days I've had a thick white discharge and burning when I use the bathroom. Is there anything over the counter that works well or do I need to visit my doctor? Also before this started I regularly had a clear watery discharge with no odor. Not sticky or stringy just clear and watery. Is this normal? I've been to the doctor many times and tested for bacterial infections, etc and nothing has ever come back with anything. Please help. Need advice in the meantime until I can get to the doctor.