Yes, it updates daily and checks for updates more frequently as many different components update at different intervals.
If your user interface is green and states that it is protecting, you are fine.
I suppose you are referring to your Anti-Virus Updates? It is normal for this to occur in order to keep you current/up to date. Could you kindly provide a Screenshot of your Ant-Virus Build/Version?
Are the updates completing their install?
Also if your User Interface shows that your computer is Secure, then all should be fine.