Go to Account Settings > Shareable Dashboards to see all your shared dashboards' status. You can activate/deactivate them whenever you want, and you can also get extra info about each shared dashboard (the date it was shared on and the shareable link).
Keep in mind that once you deactivate a dashboard, the people you shared them with will not be able to access it. You can also create a new link for your shared dashboard each time you want. Here's how to regenerate the link for your shareable dashboard.