Soo guys. I feel kinda dumb because I was so convinced it was a chicken egg..
But I found another one today
View attachment 2006750
Alright, it can't be a chicken egg. They couldn't have layed an egg this small twice in a row! I opened one of them..
View attachment 2006758
Couldn't get a better photo, but the egg shell is much thinner than I thought but was still very though... And some small blood vessels. Well, I should have tried candelling it or something before opening it( feel really bad now.
I'm pretty sure it's from a gecko, and I might try to hatch the other one? There's definitely something going on in there, some blood vessels and some development.
I think what caught me off guard was how similar the colours were to my actual chicken eggs, and how strong the shell was for such a small egg.. And also how I found it with the other eggs!
I'll go look tomorrow to see If I can find any others buried in the straw.

Reptile egg makes perfect sense, tough, thin shell, etc..
I love house geckos. Do you have any living behind pictures and mirrors in your house?