Hey! You mean the Menstrual Cycle Tracker app on Sim phone? That option should be visible for any Sim that can get pregnant. Could you open your Sim in CAS and check if they are set to be able to get pregnant? And if so, switch it off and on again? I've revived a few odd reports about it, but I don't know of anything that could be causing this.
And the 14th update is the latest version.