Summary: 

How to use the Transaction report to review what Products have been shipped in a specific month

Steps:

The Transaction Enquiry report can be used if you would like to have an overview of what products have been shipped in a specific month.

The Transaction Enquiry screen enables you to view all Completed/Dispatched/Receipted transactions (any open transactions are excluded) based on the filters specified, in your case in the "Transaction Type" field I would select the "Sales Shipment". 

This transaction type will then show which products have been shipped regarding the status of the transactions.