There are a lot more factors that go into rebirth than having children. What is the quality of our consciousness before, during, and after the moment of death? How conscious are we during our lifetime? What actions do we perform and what are their results?
Karma is complicated. To really know where we will go, we must awaken within the internal worlds. Divinity can guide you about your trajectory and what you must do to ensure a positive rebirth.
For thirty years I sought God. But when I looked carefully I found that in reality God was the seeker and I the sought. -Bayazid al-Bastami