nope. not sure of the number but it's not even close, after some quick calculations, since the guy does most of the work and assumming a 180 pound guy having sex for 60 minutes straight should burn between 250~300 calories depending on ho hard he is putting it to her.
There is however a small grain of truth to your statement, in that the calorie that everyone understands is actually a kilo-calorie or 1000 calories a single calorie is the equivalent of the amount of energy required to raise the temperature of 1 gram of water 1 degree celsiuos. So 3000 calories in the scientific sense would = 300 calories in the everyday knowledge sense.