Hello, this is my first time incubating eggs and I have two mallard ones that were abandoned. Development and movement of the embryo has been great, but we are around day 19 and I'm concerned about the size of the air sacs. They aren't tilted at an angle like the photos I've seen. Ive tried to keep the humidity at 55%, but my incubator had fluctuated a lot, especially at night. Is it too late to do anything to fix this?