Sharon I moved your post to this forum hoping you will get more reviews and input for your question
I think Discus are like angelfish in that you can't tell which is male or female until they are observed spawning.
Actually Angels and Discus are both in the Cichlid family and so have some similarities and one of those similiarities is not being able to tell whose who until they spawn
Do you have pictures of your Discus? we would love to see them.