Are they laying?

I got the new batch of pullets in March.  I wasn't expecting any eggs from them until August.  Yesterday I got a small egg.  Is it just a fluke?  Every now and then, the mature hens will lay a teeny tiny egg, but I don't remember ever getting anything but white (Campine) eggs in size XXS.  I am hoping that my new girls are starting to lay. 

Here is a pic of two eggs from the mature hens, plus the little tan egg I got yesterday.  Is this the start of something big?