One of the chicks pipped hours ago and has been trying to steaily work its way out. Hasn't zipped yet, but as I was watching, browning/yellowish/orangy liquid glooped out of the hole. It had pipped higher up but the egg got moved while another was hatching so the hole is down towards the bottom (still zippable). Quite a bit of this liquid came out. What is it and should I worry?