The couple, who are already proud parents to North and Saint, however did not know when it would happen, reported Ace Showbiz.
"Kim has had alternate feelings on a third child and still doesn't know what she wants to do," a source said.
The source added that the "Keeping Up with the Kardashians" star was still hesitating over whether she's ready to conceive again because she apparently had some hard times during her pregnancies.
As previously reported, Kim had some problems when she gave birth to Saint, including placenta accreta, a condition where the placenta grows too deeply into the uterus.