New construction is tricky - if you "registered", ie provided your contact info, and I think even your name and phone number may constitute a registration, they may not acknowledge a relationship with a buyer's agent, and by that I mean they may refuse to pay the commission. I even ran in to a situation in which a buyer of mine stated he was working with me but because I did not accompany them for the first visit, they refused to acknowledge our relationship. If you are registered, I do think there is some sort of time limit on it.
My suggestion is to call the office and explain that it was not your intention to work without a buyers agent and see if you get anywhere. Talk to you agent for guidance as well.
But generally with new construction, those are the rules - to all buyers, PLEASE remember this so that if you are driving by a new development it is probably that your agent must register you and/or accompany you on the first visit.
Thanks for asking this question.
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