Today, while on the highway my mom, how was following me, called me and said something was leaking. I pulled over and realized it was coolant. We were almost to our destination so I grabbed some water and extra coolant from the gas station and headed out. I was paying close attention to my gauges and they weren't going up. The heat gauge stayed just below the the middle range. The heat however stopped working. I could turn it on and get a good blast of heat for about 3 minutes before the cooler air came. I added more water after we stopped and after a short time away, I came back and there was a small puddle. Nothing too extreme but there none the less. Before the journey back I added more water and after about 40 miles of normal driving with some lights and stop signs, I made it home. The car NEVER overheated and I didn't have to stop anywhere in between. I'm not sure what's going on. I'm thinking maybe the heater core or possibly just a hose. The leak "seems" to be passenger side since that's where the puddle is. I had the water pump changed 2yrs. ago. Any ideas would be GREAT!! Thanks in advance.