How to access the certificate information
  1. Open a site in Google Chrome.
  2. In the address bar in the top left, click the lock iconLock or page iconBlank page.
  3. Click the Connection tab or the blue Details link.
  4. Depending on the site, you'll see two or three sections of information and a summary at the top highlighting important issues.
  5. Click View Certificate
  6. Observe Valid from dates

Please see the following Google Support article for detailed information on this process

In addition, you can input your website domain into this SSL Server Test