That depends on what exactly you pasted and what wallet you used to send the transaction.

Please share with us as many of the following as you are willing to so that we can better answer your question:

• Address you intended to send to
• Address in your wallet that you originally received the bitcoins into
• Which wallet software you are using
• Transaction ID of the transaction that you sent
• The 69 characters that you pasted into the address field when you sent the transaction