Notices
If I simply change my password am I supposed to be getting the notice that my Apple ID is now being used for iMessage and FaceTime on a new device?????
You might. I have had that message before. Check your device list to see if there is a device signed in that you don't recognize. You can remove the device using the steps in the article below. As a precaution, change your password.
Apple ID device list -Check to see where you‘re signed in.
What to do after you change your Apple ID or password - Apple Support I suggest doing this before you change your Apple ID or password.