>I didn't do any backup.
>I only got a log file (I think)

Too bad for you. You should consider doing regular backups because you never know when you will need one.
You may want to check the Log Explorer from http://www.lumigent.com/products/le_sql.html and Apex SQL Log from http://apexsql.com/sql_tools_log.htm that allow to view a transaction log. I'm not sure if they would be helpfull in your particular case but it worth a try. The Apex SQL Log has fully functional trail version. The Log Explorer has evaluation version also.