Our founding fathers very specifically crafted the protection against self-incrimination located in the Fifth Amendment with a purpose. The protection dates back to English common law when the courts sought to prohibit the use of inquisitorial methods of interrogation. By the late 1700's, Parliament had begun to recognize the presumption of innocence. Of course, these ideas were carried over into colonial America and adopted into our Constitution. Through decisions of our Supreme Court, the protection of the Fifth has been well grounded and preserved. Justice Frankfurter, in Ullmann v. United States, 35 U.S. 422 (1956), stated:
"This constitutional protection must not be interpreted in a hostile...spirit. Too many, even those who should be better advised, view this privilege as a shelter for wrongdoers. They too readily assume that those who invoke it are either guilty of crime or commit perjury in claiming the privilege. Such a view does scant honor to the patriots who sponsored the Bill of Rights as a condition to acceptance of the Constitution by the ratifying States."
There is no shame or presumption that a person must have done something wrong or must have something to hide just because someone utilizes his or her constitutional right to remain silent.
In fact, I would advise you to never speak to law enforcement without having a lawyer present. Far too often, your words will get turned in such a way that you never intended. People tend to believe that since they are innocent and have nothing to hide, it is okay to speak to law enforcement. Then the next thing, they know, they are in handcuffs, being charged with a crime that they did not commit. You have the protection of the Fifth Amendment for a reason. Use it!