How do you know if an egg has gone bad? What do you look for?

Yep, that's a sign that it's an older egg. Always crack each egg in a different bowl than what it's going to be used in.....in case 1 is bad you don't ruin your whole recipe. Since it didn't smell it would probably be okay to use in baking.....but tossing it is always a better choice when there is a doubt!