Today is day 18 of my hatch and I'm very nervous. On day 15 I candles all of my eggs and each one looked great. I saw the large mass and a ton of veining. I even saw one move. Now today before I locked down, I candles them one last time... I still saw the mass and a defined air cell but I could only see one tiny vein in one egg looking very closely. The others I saw absolutely no veins. Is this just me not seeing correctly or should I definitely be able to see veining on day 18? Any ideas? I was so excited and now I'm kind of worried. There was no temp change or humidity change at all.