Hi, and thanks for your medical question on eHealth forum!
The yeast infection could still be persisting if you have a foul smell discharge. Yeast infection or thrush is at times very difficult to treat. You may need to take oral antifungal pills twice a week for 3-4 weeks along with local application of antifungal cream. At times both partners need to be treated. The other possibility is that it is a STD. Discuss this with your gynecologist.
Hope this helps. Take care!