Egg disappeared from under hen

[jutebox]

Hi I have a question I have a hen and rooster in a playpen in my house .They are little I guess they miniature but it is too cold from them to be outside any way she laid nine eggs its has been three weeks since she started to sit on them. They both are keeping them warm .Well this morning there was only eight I tore the play pen apart moving the straw but the ninth egg does not exist I can't find it not even a piece of shell . Can someone tell me what has happened to my invisible egg . If it was the hen or rooster what do I do now .I have never hatched eggs and no nothing about it except from what I have learned from BYC . PLEASE can someone tell me
what I am suppose to do now with the last eight eggs ? Here is two photos to show you how small they are .Please meet Mr. and Mrs. Minime this is how he sleeps with his Mrs. I have no idea what bred chicken they are. P.S Sorry I have no idea how to do this letter or photos

 

[TheKindaFarmGal]

If it has been three weeks, then maybe the egg hatched and you just didn't see the chick. They are easy to miss. If that isn't it, then likely the egg got stepped on, broke and eaten, which is pretty common. You don't need to do anything.