Why is the number I am in line to receive the item not showing up under "Holds"?
Login to your library account at https://cbcl.sdp.sirsi.net and then click My Account. Under the Holds tab, you will see a column on the right labeled Place in queue. That will tell you your position in the line to receive the book.
Remember, if we own multiple copies of a book, you might receive the hold notification earlier than you expect. For example, if you are #20 in the queue and the library owns 5 copies, your position is the queue is closer to #4.