Antifreeze Leak

[EquatorHeat00]

Joe explain this. Car hasn't leaked antifreeze in almost 3 weeks now, and car drives great with no stumble at high rpm's. BUT I still get the Low Coolant light on whenever the car is cold NOT warm. Bad sensor possibly? Is this related to my thermostat change back in late spring. Could I possible have had air in the system for that long a period of time, and would air in the coolant system cause a stumble? Then filling it up about every 3 days on average for a month, and a half.