this is so wrong and I can't believe I have to correct this (I was thinking of skipping to correct earlier).
After "Try for Baby" interaction, yes, there is no "pregnancy test" option when you click on the toilet. But you are wrong, the "pregnant test" option on the toilet will appear about few seconds after "try for baby", not immediately.
I don't consider this as a bug at all because there are a lot of options/interaction usually appear a few seconds after an interaction which is quite normal, it is quite normal that the game takes some time to process an interaction, especially if your lot is very full of items (your computer will take longer time to process an interaction in a lot full of items) and/or you are using a low specification computer to run the game.
In short, in conclusion, this is not a bug, the option "pregnancy test" does appear a few seconds after "try for baby" in my computer.