One thing is sure, they look as the first day for non experts! However, there's a clear indication at the package that says more or less 4 or 5 weeks if they are stored in the refrigerator at around 5ºC. Some people do not take care of these indications and establish a do it yourself method to give the egg a go or no go policy. Is this safe? What factors are involved?
We think this is a good question because sometimes to ignore something could be really problematic, especially when it converges with the human organism and its complex processes during long periods of time.
This time, let's trust what a specialized web page adverts:
As long are they are kept refrigerated at 45 °F or lower, fresh shell eggs are safe to be consumed four to five weeks [...]
It means after the date of packaging.
Perhaps this is also relevant for your experience with eggs; like it says:
If the egg is not clean, it could carry other kind of contamination, so it's a good idea cleaning it and wash your hands before touching anything else.
With a more technical approach, with specialized equipment, there are possibilities of discovering several kinds of microorganisms and a surprising complexity inside the egg. More of this in the next article: Some details of egg conservation II.