I recetly got one broze badge in stackoverflow making total of 12 but I dont know which one I earned. There should be a kind of notification for such kind of event.
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You have several options:
Look at your activity tab, awarded badges are named there.
Look at your badges tab, sorted by recent. The top-left badge is the most recent.
Look at your notifications, the exact badge you earned is named:
Note that once you associated your account with multiple Stack Exchange sites, you no longer receive notifications for certain 'low level' bronze badges to cut down on the noise a little. See Prevent the 'Notification Fiesta'