check your oil level, see if it has dropped, if it hasnt, i really wouldnt worry about it.. twice in 200 miles? dont you think if you had a leak it would occur more often? its ok that your paranoid, check it out just to make sure, but honestly i dont think this is as bad as it sounds
secondly, does it only happen if your heater is on? if it does, it may have somethign to do with your heater core(even though that is the cooling system)