Hello!
Do not worry about that. I did the same thing and the icon took about 1 week to appear. You probably have to wait till it appears.
If you do not want to wait, you can already download it here:
https://www.microsoft.com/en-us/software-download/windows10
I'm not 100% sure it will work though, since the icon didn't appear on your computer just yet. But you can give it a try.
P.S.: If I was you, I'd stick with windows 8.1 for a couple of weeks more since it's probably still very buggy and unstable.
Let the others work for you and test it, stick with the stable windows 8.1 version for 2 weeks and then download it