Don't worry, if you try to reinstall (with your save files backed up) and reinstall version .04 this could help learn a bit more.

If your couple is able to try for a baby after the reinstall with the same version, this could just mean one of the game files was acting up. If it doesn't work, this could either be a version-specific issue or something located in the savegame files which I really hope it isn't.

Best of luck! Best case would be the working reinstall of .04