Asking "Am I being detained?" is useful for establishing the terms of a contact with the police, but repeating it every few seconds isn't particularly useful. Making it clear that you don't intend to have a conversation is much better. Then the cop can decide what he has and what he intends to do.
Then you keep asking "Am I being detained or am I free to go." If they want to play games just invoke the Fifth and STFU.
Asking "Am I being detained?" is useful for establishing the terms of a contact with the police, but repeating it every few seconds isn't particularly useful. Making it clear that you don't intend to have a conversation is much better. Then the cop can decide what he has and what he intends to do.