Katherine | Hal
I think its not a decision you should even attempt to make yet. You've been human mere months and Elijah is far from that. If the opportunity presented itself I think you would jump at it and then be left with the consequences even if they were not what you'd hoped.
If you're that close to telling him so, then you aren't ready for a child. Because any child you have now would be human. Are you prepared to see it grow old and die, or would you turn it as well once it came of age?
I don't think you have thought this through at all. More to the point, how can you even be sure Elijah is the one you want to have a child with?