Are your eggs stamped? You can use the code to find out date of production, etc. Probably each country has their own way of doing it, but in Germany the web site to find out is
You can try to find a similar site for your country.
Otherwise, you can also look at the egg in strong light and see if you can see air in the egg. As an egg gets older, you will see a bigger pocket of air in the shell.
I don't refrigerate my eggs because I buy them individually and use them individually and quickly. But I do check each one before using, just to be safe.