The phrase "am led to believe" implies that the speaker has formed a belief based on information given to them. Therefore, antonyms for this phrase could include "am convinced otherwise," indicating that the speaker has since been given contradictory information and has changed their belief. Other antonyms might include "am skeptical," suggesting the speaker is unsure of the information they have been given, or "am uninformed," indicating that the speaker has not been presented with enough information to form a belief at all. Additionally, "am misled" could be considered an antonym, as it implies that the speaker was given false information that led them to form a belief that is now untrue.