If you have a contract, no, if you only have an offer, yes. My question would be, how can an agent submit an offer you weren't ok with? An offer requires your signature, if you weren't ok, why did you sign it? Sounds to me as if the agent was doing their job in finding a buyer that was ready, 'willing' and able to make the offer....are you sure you're not just having second thoughts???? Many times all of us have these feelings, just second guessing our decision, thinking we could have made a better deal!!!
Best of luck in your home search!