try getDatabasePath on ContextWrapper ( http://developer.android.com/reference/android/content/ContextWrapper.html ). If you are in an Activity or Application class try:
File dbFile = getDatabasePath(MY_DB_NAME);
Log.i(dbFile.getAbsolutePath());
Just assuming its in /data/data/my.package.name/databases/
is bad as there is no guarantee the data has not been moved to the SD card or the device/OS has just decided on a different data directory.