My BLRW is 36 weeks old and not laid her first egg. She is acting odd and I was hoping it's an egg coming on, but now I'm not sure. She looks perfectly healthy, but is spending allot of time under the coop in her home-made nest, and when she is on the nest it looks like her back end is pulsing up and down like she is working to push something out. I thought "this is it, egg time", but she has been doing this for almost 2 days. Should I be concerned?