indesign layout changing when I insert pages

Hi,

I have a magazine where I have inserted new 2 pages and suddenly my one layout which was on a spread has changed appearance eventhough still on a spread. After inserting the 2 pages the layout was not on a spread but I moved a page so they would be again. This resulted in the layout being different - some text is now beneath a shape etc. How do I avoid this in the future? 

I guess this has to do with the adjust layout feature which I am not accustomed to using. 😞