I am unsure what the problem is. MySql doc says:

For LAST_INSERT_ID(), the most recently generated ID is maintained in the server on a per-connection basis. It is not changed by another client. It is not even changed if you update another AUTO_INCREMENT column with a nonmagic value (that is, a value that is not NULL and not 0). Using LAST_INSERT_ID() and AUTO_INCREMENT columns simultaneously from multiple clients is perfectly valid. Each client will receive the last inserted ID for the last statement that client executed.

Out of curiosity, why do you even care what the last auto_increment unique number that your client used was? Why does it matter to you? Other clients could be many, many numbers ahead of you. You can know this number for your last insert, then I guess you use that as a field for an entry into a different table? But why would you want to do that?