I am new to hatching but I am trying to hatch buff ducks. Last week I lost one during its zipping stage and then a chick died in the shell before it even pipped on the same day the zipped one died. Today our 3rd egg was moving, etc. and now there is no movement but there is a ring around the egg where it should have zipped but it didn't zip or pip - did it die? What am I doing wrong? The temp. is 99.5. (its due date is today). This is so frustrating. Any advise is appreciated.