Although the odds of your website being impacted is less than those that do not have a mobile or responsive site at all, that does not mean Google might not have troubles with some of your mobile pages according to their new guidelines.
It is highly recommended still using the tools mentioned below to test the site for errors.
• How can I make sure my site does not get negatively impacted by the Google mobile friendly update on 21/04/2015
• I did the Google Mobile Friendly test and it said “Awesome! This page is mobile-friendly.” Does that mean my website will be OK after this update?
• I already have a responsive website, or standalone mobile website, do I need to worry about the Google mobile friendly update of 21/04/2015?