I found this site to be quite helpful- someone else had posted it for something once. It ha exceptional info on the chicken reproductive system. If you read all of the problems and bookmark it, you might not only find the answer to your problem, but also know about other things before they happen so you will recognize them...I'm not through reading so I can't actually offer you a solution, but it may help you to have the site. Good luck!
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/toc_205800.htm
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/toc_205800.htm
