There are a number of online tools you may be able to find that can analyze your file
This guide will show you on Adobe Reader / Acrobat. Once opening the file, if you navigate to the File menu and then to Properties. (Shortcut Ctrl + D).
You will then get a box that will pop up like the below with a sub-menu at the top. If you select Fonts at the top. It will load all of the files that are present and identified in your file. Against each font, it must indicate either (Embedded) or (Embedded Subset).
