After having a complete mastectomy, there are various choices available. Reactions to the loss of a breast or breasts vary from woman to woman and only you can choose what feels best for you.
You might feel quite comfortable wearing an external prosthesis (a breast form) in your bra. A good prosthesis not only helps with your appearance but also helps you to maintain your posture and balance. Many women choose this option. Others choose not to wear a prosthesis at all, and still others choose to have a reconstruction.