I never say there is no bug for everyone.
I did "try for baby" for 5 children (which is more than most people did "try the baby" here), all has the option to take pregnancy test, so it is very weird.
It is not surprisingly that probably "half" the people here did not come back to the toilet to check few seconds after, as the option to take pregnant test doesn't appear immediately after try the baby, it only appears a few seconds after. The game takes some time to process the interaction, like I said previously, especially in the lot of full of functional items and decorations (it is laggy), and this is NOT the only thing an option doesn't appear immediately, this is NOT the only thing an option only appears a few seconds after, the game takes time to process them.
Maybe it is indeed a bug for some people after coming back to check after a long time (not immediately after), but it really doesn't matter, since you can check whether a sim is pregnant by selecting "change sim" on a closet or certain type of mirror, go to the part where you can change "make others pregnant" or "become pregnant". If the sim is pregnant, they won't allow you to change. If the sim is not pregnant, they will allow you to change that.