So from what I understand you're 18. You wanto have sex to produce a baby or your body does.
So what is your body saying that it wants to have a baby?

You said mentally & emotionally you do not wanto have one. Honestly I would side with these bec of the huge implications of having a child at your age...although I don't know all the details.

If nothing turns you on sexually & you're not having sex does this matter?
Are you saying that nothing turns you on if you wanto masturbate?
That your libido is low?
I think there's more questions here that need to be answered on how you're feeling.