Google Calendar Embed partially hidden behind header

Hi all, hopefully simple request.  Embedding a google calendar on the site with the standard iframe code block in the Page Header Code Injection section.  Using a simple header with fixed position enabled and header style basic.  

Tried about 20 different code snippets and no matter what I do the calendar top is hidden behind the header.  Can't space it or pad it down no matter what I try.  Any ideas?  Thanks!