"Try for Baby" Broken?

[Mande]

So I have had this problem on three game files so far and I am wondering if it is happening to anyone else.
When I click "Try for Baby" I never seem to get the chimes! They are always married Sims, with a maxed out relationship. The house is not full its just the two of them. They go through the regular "Whoohoo" stuff but no chimes... I've tried many many times and still nothing. Both are young adults and I even gave the fertility treatment to the girl and still nothing.  I am starting to get very frustrated. The latest couple I am having trouble with is in my dynasty game, and because this is my 6th or 7th try for a dynasty I really don't want to start over again.  

Any advice would be very appreciated!

EDIT: I forgot to mention that I do not use MODS or third party CC.

[Alexandria_]

Sometimes babies can be conceived without the chimes playing. How much time have you left between the tries?

[Lilygirl]

I usually have them try for baby 3 times in a row if I don't hear the chimes and then give it 24 hours to see if she got pregnant; and if not, then it's back to bed for a few more tries.
I've had pregnancies before that started without chimes so it does happen. Is it your Sim with the fertility treatment that is initiating the try for baby with her partner?

[malteser60]

I don't always get the chimes either. Especially if the try for baby happens in the science building, theatre, etc.

Also sometimes the die roll just goes wrong. My first dynasty I had the daughter marry the maid and shortly after decided to go for babies. It took 25 woohoos, 25, before finally she got pregnant!

[AriaGirl77]

I suspect that trait compatibility may have an impact on how easy or difficult it is to have a baby.  Perhaps even "signs" now that we have them thanks to LN.  I've noticed that for some couples it's no problem at all, and for others it takes a lot of time and effort.

Probably just EA's way of trying to make the game more like RL.

[Naga]

Give the guy Fertility Treatment too, and (not sure if this affects anything) make sure none of them have Commitment Issues or Dislikes Children.

[Mande]

My Sims are always at home in the bed when they Try for Baby, So I thought that I should be able to hear chimes if it worked, also in my past games if the action worked the Try for Baby option was no longer there.  I have had them both initiate the action and still no luck.  I don't want to give the husband the Fertility Treatment also because then I have the risk of triplets and in a dynasty game that just wont do!  I am about to load up my game again and give it yet another try!

[Teresa]

In Sims 3 the try for baby option does not always go away once a baby is on the way.  Also I only get chimes a third of the time and if I have queued up the option several times I can even get the chimes more than once.  Generally if the timing is important I will queue up the option 7-8 times then let them go until I finally get the chimes just to be safe.

[Mande]

First let me say thank you to everyone for the replies and advice.  I finally got my chimes and twin girls was a result.  I guess it makes sense that you wouldn't get chimes every time, I just seem to remember in my past games I always got them and usually on the first try. It just seems to me that as of late I am having to make them try for baby a lot more before it actually works.  

There is only so much time in a day and as much fun as my Sims think it is, I can't have them in bed trying for a baby all the time they have important thing to do!   This is my dynasty game after all.