2001 Honda Civic AC not working

AC just stopped working half way into a 20 minute drive on a hot hot day in texas. The cold air just faded into hot air. That night it seemed to come back on for a few and the next day it came back on and started blowing cold again for about 15 minutes before going back to hot again. I know AC systems don't "use" refrigerant and since it came back on and worked for a while I dont think it needs a recharge. When I turn the ac on now, I can hear the fan engage and the engine increases its idle however still no cold. Help! I don't have a lot of money to spend replacing compressors and such.