Immediate Welcome message after signup- change it?

I have installed the
remove email verification AND
Login redirect on this site:
http://polymerclayadventure.com/classroom

Why are users being shown the welcome page with this message:

Check Your Email To Activate Your Account!

You have successfully created your account! Please log in using the username and password you have just created.

Instead of being redirected to the page I want them to go to (registration page).

If they must see the welcome message how can I change it? I want it to say to go to the Register page, preferably with a link, so they can finish buying and not drop out of the purchasing flow. This message is currently confusing to them. Thanks!