If you look at this little egg closely with a loop, you can see tiny capillaries with black specks which are probably red blood cells. They actually look like worms. This was one of the first eggs I cleaned and so I left a lot of the baby Dino Do-do on it.
The picture above shows the flat side. There are tiny black specks in the fluid there, too.
Another view of the back and the flat spot. Below shows nice layers of the fluid and shell.