My attorney would strenuously advise you NOT to open your door when / if any cop comes knocking. You have NOTHING to say. (If the cop had a warrant, he would be coming in and you'd still have NOTHING to say. You'd call your attorney to meet you at the station). But there is not going to be any warrant in your case. Seriously: Do not open the door to a cop. Trying to explain your side of a situation to a cop can be a very foolish thing. My attorney said he makes a fortune getting people out of trouble when they've tried to talk their way out of a situation - to a cop or detective.
My cousin is a judge, and he said it is normal for people to feel that a cop is a nice, neutral, bright guy - who - when he hears the story, will understand, and everything will be alright. This could go badly for you. The cop comes out to hear a complaint, and decides quickly who is the good guy - and who is the bad guy. The complainant is who the cop hears first. You - the defendant are already in second position. If the cop has already decided the complainant is the "good guy" then nothing you say will be of any use. The cop will actually use anything you say to work the case against you. He may even decide to cuff you and arrest you for being belligerent. My cousin warns that the cops are not usually nice, neutral, bright guys. He warns that many cops took that job because they couldn't do anything else. Not all - - just most - - he said.
The advice from my attorney and my cousin (the judge) is to NOT open your door. Even if the cop knows or thinks you're home - - - stay away from the door and windows. He cannot hurt you without a warrant. He CAN hurt you if he doesn't like your story. You do not want to answer his questions. You have nothing to say. Remembering this will save you a fortune in legal fees, and maybe a night in jail. People do not have to talk to the police.