I think it fell in the water or got washed away. It is definately fertile and it has grown since I found it. I also read that the white strip means they're fertile.
Here is a pic of it being candled. It is pretty young and all I have to candle things is a flashlight, so it doesn't show up very well. If you look closely at the middle you can see the veins


I'll post more pics in a few days to show its progress. I hope it hatches too