But don't look for it in the App Store. Instead, ope System Prefs and select "Software Update". You may see you are up-to-date, but wait a few seconds and Apple will "hear" you asking and you will now have an "Update Now" button. Details are at
https://support.apple.com/en-us/HT209149.
BTW, the Combo updater, which I will be using, is here:
https://support.apple.com/kb/DL1987?locale=en_USNo rush, I'll wait a few days to see how you bleeding-edgers do (and hopefully report any problems).
If you haven't updated to
Mojave macOS 10.14 yet, you should still be getting a Security update for
macOS 10.13 High Sierra and
macOS 10.12 Sierra as well as an update to Safari. Those should be in then App Store.