I found this mallard duck egg alone on the concrete pool deck. I had a couple of mallards hanging out at my pool for weeks and she would leave random eggs around so I decided to attempt to incubate it. So we are on day 19 of when I placed it in incubator. I have candled it a few times and always see growth and lots of movement. Amazing! So I hadn't candled it in 4 or 5 days and decided to take a peek tonight. The egg contents are very dark. I see veining and an air sack on the end. And lots of veins in the egg. Its just that the egg now has very little clear to it? Last time I looked it seemed half of it was clean and other half was yoke and baby. Now it seems whole thing is dark but for the air sack and a tiny portion of the white. Rest looks dark red in there. I do see movement. Is this normal? I thought I saw a small vein that looked like it was leaky or had a blood clot in it? Not sure if its my imagination or not. Is any of this normal or am I losing my little duckling?