I think stillbirths are not wholly abnormal...I'm no expert by any means but every birthing we've had since we started (with the exception of the first one that we didn't know about till after it happened) has had several stills at the bottom of the box. Just about half it seemed.
As for the delay in the birthing, I have found that, unless the folks at the LFS actually witnessed the conception, they might not be all that reliable in determining the due dates. We purchased a pregnant molly for our son and was told she was at least 2 weeks away from birthing, then lo & behold 2 days after bringing her home she birthed. And we were wildly unprepared! We weren't able to save any from that birthing - they became hors d'oeurves VERY quickly
