I forgot my username on instagram, but I know my password?

[Sam]

To determine and locate your Instagram without your username, you simply visit an URL shared by instagram on other social networks. Alternatively, you can ask a friend on Instagram to tell you how your name appears.

If you are receiving a "No Account Found" message, or if the account that is returned is not yours, try locating your account through one of the following:

Search by your email address.
Find the URL for a photo you previously shared with friends, or on another social network like Twitter or Facebook. Usernames are listed at the top left of the photo page.

-http://help.instagram.com/374546259294234/