You can keep track of all retests on your projects by clicking on Retesting module from the main navigation menu.
Here you will find a list of all your projects, including columns at the end (far right) which you can sort by and includes:
number of vulnerabilities flagged for retesting on the project;
number of round of retesting requested on the project;
number of rounds of retesting completed on the project.
You can click on any of the numbers in order to drill-down to the details on the projects.