Thanks for the query.
Yes, curdy white discharge is a symptom of the yeast infection.
So you continue the tablets prescribed by your doctor.
Women with IUD are more prone for pelvic inflammatory diseases.
So you better undergo ultrasound
as adviced by your doctor to rule out PID and also to confirm the position of IUD.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429