Lost my streak when working on it every day
I worked on my Italian every day since I started, 23 days ago. Yesterday, after logging into a different computer, which said "Streak 0 days", I logged out of it and logged back in on my usual one. My streak was still at 0.
I'm not part of the tech team, but they will want to know what operating system and browser you're using.
Here is information on how the Streak works, as it has some guidelines http://duolingo.wikia.com/wiki/Streak
Additionally, it's a good idea to keep a Streak Freeze on hand for occasions like these. You can purchase it in the Lingot store for 10 lingots (here are some lingots to help you). To read more about how the Streak Freeze works, go here http://duolingo.wikia.com/wiki/Streak_Freeze
I hope this helps! :) Oh! And feel free to donate 10 lingots to someone else in the future when you've got a few extra to spare. ^_^