odd eggs please read and let me know if anyone has had this happen

[leeboyz337]

so i have 4 buff orpingtons and 2 rhode island reds that are 23 weeks and they just started laying this weekend and out of the 6 birds ive gotten 7 eggs and one was the largest egg ive ever seen. when i cracked it there were 2 yolks and the birds have been on organic feed since the day they were born. any ideas as to if this is normal or may happen again? and if if does and i have a rooster in with them can you have twin chicks? at the same time i have a year old black ostralorp and she laid the smallest egg ive ever seen and she normally lays jumbo size eggs. what may have caused this? thanks for your time and the help.

 

[southerndesert]

You always get some surprises when a new batch gets to laying well, enjoy the double yokes while you can all sounds normal....