I posted my problem with "Shell less eggs" as a subject yesterday.
Today I use this subject so that it can attract more attention. Please follow. I am really worried.
This is what I wrote and the responses I got:

Some days ago I posted that my rooster (Felipe) swallowed a big chunk of Styrofoam. Well, there were no consequences other than that I found out that roosters are not allowed in my area. So, yesterday (sob X 6) (three sobs are mine and one for each of Felipe's wives) I give him to a friend who swore Felipe will not be invited to dinner.
Well, to the point. This morning I found THREE (3) shell less eggs!!!
Possible causes?
1) Last night was the first time Felipe was not in his perch surrounded by his amorous wives.

2) Last night I forgot to close the door of my coop (not the first time).

I know its not rare to find an occasional shell less egg; but three out of three in the same day???

Any one of you guys have had a similar experience?
Felipe and wives are ameraucanas

Response 1:
I'm not a chicken person (other than to eat them), but I must say that Filipe is much too handsome to eat!

Response 2:
When my pet duck started laying shell-less eggs I took her to an avian vet.
She said it's not normal & indicates some problem with lack of calcium or calcium adsorption.

So make sure your hens have free access to calcium & other minerals & vitamins that affect it. Most folks give chickens oyster shell grit. If they are yard hens, they'll pick up vitamin A & D3 (often too low in all-grain diets) from greens they pick at. Chickweed, that is a winter annual down here is very nutritious. Kitchen scraps like vegetable trimmings are good, too.

If you're getting shell-less eggs on a regular basis, there might be some sort of metabolic problem. But it seems like if all three laid them, at once, maybe it's more nutritional.

Does seem odd that all three coincided with Filipe's removal--maybe stress can cause that, too--poor chickens.

Then I wrote:
Thanks Blue Girl.
One thing I did not mention was that I was trying to make sourdough bread (following Amy's recipe I found here in GW, that uses rye flour) , the discarded portion of the starter went to the compost pile where the chicks have access. Now, rye and other grasses like oats are prone to get a fungus named Claviceps purpurea (I do not know the common name in English) which is known to induce miscarriage in cows and sometimes it was used to induce abortion in humans..
I used organic rye floor. Do you think that could be the cause.
My chickens have access to a lot to weeds and trims from my garden, Their egg's shell are noticeable harder than the eggs I used to buy (its my only experience with ameraucanas then I do not know if the hard shell is normal for this breed.) In one word malnutrition is discarded. Besides, a shell less egg is not too common and as you said ALL THREE in the same day...??? I can bet the probability of that event is smaller than one in a million.