Media Formatting

Whenever I create a new post, input a media image, and then publish, the picture gets sent to the right hand side of the post. I have the post format as full width and center justified. Instead of inputting the image into the actual blog post, it always sends it to the right hand side. I would like to know how to remove this formatting so I can have writing—>image—>more writing etc. in my actual post. Thank you for your help ahead of time. ??