i have a pulsating green dot in the center of my watch face? what does it mean?

The small red dot icon (which may appear, to some users, to be green) at the center top of the watch face indicates that you have one or more unread notifications.

To open Notification Center and view your available notifications, when viewing the time on your watch, swipe down on the display, then tap on each notification to read it in full.

More information:

About notifications on your Apple Watch - Apple Support

So post a screen shot of what you are seeing thanks

Ok great. That is where you are in the world right now. It goes away when you have a different Watch face?

It sounds like you have breath app on. Post a screenshot of what you are seeing

No don’t worry. I would have not know it unless I saw the picture. At least now you know what it is. If you turn the crown the day changes to night as the darkness comes across the earth.