Ok I *think* have found a solution to the problem of getting into Pottermore. Mine was like this too. But keep checking your email daily. When you get a Pottermore email the subject of the email should say this:
Your Pottermore account is ready! Step this way..

Follow the link it provides and you are ready to explore. I'm sorry I didn't say this sooner. I thought everyone got the same email on the same day as I got it.

If you still don't have your email yet, just keep on checking. It will come soon. I don't know how soon but it will come.

Again, apologies to everyone who couldn't get into Pottermore.

~Heidi