when to worry about wonky eggs?

[TLWR]

I know birds can lay wonky eggs now and again.
I have 2 chickens and they are both laying. Earlier this week one of them laid me a quail sized egg. No biggie. But 2 days later I get another quail sized egg.
I'm still thinking no biggie, but DH suggested asking if it might be indicative of something going on.
Not sure which chicken laid it. One is a 5 year old BO and the other is a 2 year old BR

 

[oldhenlikesdogs]

Fairy eggs can be common this time of year as many hens resume laying or increase production. They generally aren't anything to worry about.

 

[aart]

Did you open egg up and see what was inside?

Fairy, fart, rooster eggs are usually from a tiny piece of tissue breaking loose from the reproductive tract, or an immature ova(yolk) and the body forms an egg around it. Color can be darker than 'normal' as the pigment coating released has to cover a much smaller area so is thicker. Can happen with any age layer.

I think it's explained in this video, (which is worth watching even if it doesn't).
Egg Formation Video