I'm sorry, someone is messing with you (and someone who doesn't know chickens very well).
I occasionally find an egg in the middle of the yard, but VERY rarely. That is NOT where your chickens would have laid their eggs if it was them doing it. Do you have a nest box?
Can you also post a picture of the eggs next to a grocery store egg or a quarter? Those look awfully large to be pullet eggs.
Can you also post a picture of your chickens so we can see if they are even physically mature enough to be laying eggs?
Another thing you can do to see if your hens are laying is to feel their pelvic bones. If they are not laying yet, you'll only be able to get 1-2 fingers between them. If they are laying, you'll be able to easily get 3-4 fingers between their pelvic bones.