I have four Plymouth Rocks that were born in the last week in July of 2018. They have been laying since late December into January. And been getting four eggs a day for the last six weeks. The last hen to start laying, has been laying an odd egg compared to the others. They are longer and narrower, with a rough/wavy texture. Sometimes alittle spotted and then somedays are smoother then others. Also the the egg shells are fragile then others. Online i read this could be a number of things from the hen needs time to sort out her stuff, to diseases, to needing more calcium. Is there a way to determine which one it is?