Unless you have signed a buyer's agency agreement, I wouldn't generally think so. Only be reviewing your contract(s) can anyone give you a certain answer. Commissions are paid by the seller in most cases, so I wouldn't think so.
Before you do this though, why would you get this far and back out now? I would prepare an explanation for the seller and your agent. Let us know how this turns out.
Karen Paytas, GRI, CMS
Real Living Kee Realty