Provide a link to your website and I'll have a look if you like. Typically, there will be a link for login, and register in the upper corner of your site. They would both take you to their corresponding pages as desired. For the register link to be missing, I can only think of two known causes, which would be that the templates in the management settings have been edited and it was removed, or the link is the same color as your background and you can't see it but it's actually there.
A possible work around would be adding the actual login element to your webpage. It goes anywhere you place it on your sites main content area, and it also has a register link built into it that can be clicked.
