Search Warrant was never shown

the police broke through my door and searched my house looking for controlled substances. Upon entering they immediately forced myself and my husband to the ground and handcuffed us, then separated us into different rooms. When my husband asked if they had a warrant, the police responded "yes". After prompting them to show this warrant one of the detectives went outside and returned with a piece of paper with nothing on it. (not even a form that was not filled in.) Just a blank piece of paper. My husband asked what that was ,and where did it say his name, address, etc. The reply was "We'll fill that in later, you have bigger things to worry about, this is the least of your problems." We were both subsequently arrested. I was charged with several misdemeanors, and my husband, a host of serious charges. When I asked my lawyer to get a copy of the warrant, he ws unable to. I've been told that I would have to go to trial if I wanted to see that.
Now my questions: Why should I have to go to trial in order to see a document I should have had the right to see before they even searched my house?
Do you think there is a possibilty that they didn't have one? Is there a way to get this through freedom of information act? Aren't the police supposed to announce "we have a warrant to search these premises" and show it upon entering the house? I live in New York.
Are there any procedures the police are supposed to follow in this situation?