My sim tries for a baby and each time she is not pregnant.

[Dellena]

Have you tried starting a fresh game in a different world, like Sunset Valley, and see if you can have a successful pregnancy.  Remember, it takes 24 hours for her to 'discover' she's pregnant.

[pandapants33]

I have been successful 1 time with triplets.

[kusurusu]

There's a neighborhood workshop tool where you can see if pregnancy has started yet (and if you open your savegame in readonly mode you'll be on the safe side).

[Sherry]

This not getting pregnant thing, do you mean the couple got the lullaby but not pregnant or tried for baby times but not hearing any lullaby?

Sometimes my sims don't have the lullaby when they tried for baby too, but there is one easiest way to find out; just type 'testingcheatsenabled t' then 'shift and click the woman sim' see if the option for 'edit sim in CAS' still there or not. A pregnant sim can't be edited no matter what.

When my female sims tried for baby without lullaby, I type that, and if the option for edit still there, means the trying is fails and she have to try again.

[pandapants33]

I heard the lullaby but she did not turn out pregnant.

[pandapants33]

I don't know what to do. 

[LivvieLove]

You can still edit her in Create-A-Sim (via the TestingCheatsenabled True cheat)?
This is only in one file, correct?

[pandapants33]

Yes.

[jesirose]

I don't know what to do. 

Adopt?

[pandapants33]

I did was considering it but I did not get the experience of a Mom on their.

[kusurusu]

Have you tried tyger's Neighborhood Workshop? It tells you if your Sim is pregnant (and stuck progressing) or not.

[pandapants33]

I haven't heard of that.

[Sherry]

Just before this pregnant thing comes to attention, did you installing any new EP or store town or stuff pack (or whatever the name is)?

Installing new things after you play a town could cause some weird buggy issues which vary between your luck, from a job progression bar that won't move up, pregnancy that last for four days, etc, etc.

So, have you tried clearing your cache?
Or doing this the easy way : start all over again and make new save? (in case you just start playing)

[pandapants33]

No I have got an expansion pack but this happened before I got it.

[Pam]

@pandapants33:

I read through this topic and I'm really not seeing much detail from you about the problem.  Can you describe in detail exactly what is happening?  And what all have you tried to fix it?  I need lots of details.