In order to view your health records in FollowMyHealth®, your account must be connected to your medical organization. If you have never been able to see your medical information, please consult this article to see how to request a connection to your medical organization.
If you have received an e-mail saying that you have "an important message" but when you log in, nothing is there, you may have logged in with a different authentication method than you had previously used. Since each login (username & password) creates a unique FollowMyHealth Universal Health Record, you have probably created an account that is not connected to your medical organization. To verify your connections, click on "My Account" in the top right corner, and select "My Connections" from the drop-down list (see image below).
If you see either "You are not currently connected to any healthcare organizations" or your medical organization is listed with a "(Pending)" status, this indicates that the account is not connected. Since you are receiving e-mails regarding updates to your account, try logging in with a different username & password (or go here if you do not know your original username & password). Then, you can tie your working account to both authentication methods using this article.