Hi everyone! New chicken owner here and I’m incubating my first batch of eggs. One egg has a black spot on the inside of the yolk (see pic attached). Chick is alive and moving around on the other side and the few times I’ve candled it, the black spot hasn’t moved. After I took this picture, I drew a circle around the border of the spot to see if it grows. Is this something I should be worried about? Thanks!