Yeah, you don't want those. As long as you collect every day you won't get those, even if the fertile egg spends part of the day under a broody hen. Just collect every day.
But you can still get surprises. If you follow this link you can see some of them. Blood spots or meat spots aren't that unusual. People see these and think it has something to do with a rooster. Nope, not at all. Finding a roundworm in an egg is unusual but it can happen. You can read about them in this link.
Egg Quality Handbook
https://thepoultrysite.com/publications/egg-quality-handbook
The commercial egg industry candles the eggs so they don't surprise their customers. They'll sell these eggs to somebody else, maybe for pet food. This is why it's always a good idea to crack our eggs in a separate bowl before putting them in something.