My sim won't get pregnant with her husband. They both are lucky and don't have problems with children. And they both have the fertility life happiness reward. There's only two people in the active family (just them) and I try for a baby very often.
I've been doing the testingcheatsenabled code and aging is off. Does that affect it in any way?
Is the female close to becoming an elder? I think she has to have at least 3 (or 5) days left of adulthood in order to fall pregnant. Have you waited a few days to see if her belly pops? Even if 'try for baby' worked the option will still appear until her belly pops, and sometimes you might not hear the chime. Is it just them in the household? Because you can only have eight in a household, so if there's more than that then she can't become pregnant but the option may still appear.
And they are the only two in the house. And it's not anything I did. This was a pre-made family. And it says in the description that she wants kids, but her husband doesn't because he hates children. But I changed the traits. And it's been 7 days in their time.