I'm sorry you're going through this-- it would be scary and unnerving, even if you felt the docs were being super thorough.
Did you go in to the emergency room or to your OB? I would call the OB's office back and speak to the doctor on call about your concerns. I would expect your belly to be sore if you had been having contractions-- like any muscle that gets exercised more than normal, it would be sore. But if this does not feel right to you, then call. You have a right to have your questions answered.