Low Coolant Light

I have a 2001 Grand Am GT1. A few days ago, I pulled out onto the highway, had been driving for about 20 seconds, @ 50 mph, when suddenly the low coolant light blinked on for like a second. Then, a few days later, it blinked on again when I pulled out onto the road, and was going about 40 mph. This time it was on for like 2 or 3 seconds, then went away. It's come on twice for no reason, then went away. Anybody have any ideas what the heck's causing this? faulty sensor maybe? Thanks.

Mine did the same thing for the longest time untill i had a coolent flush. Every time I nailed the gas on a hard left turn the light blinked real quick then it became more frequent even when I was goin slow especialy in town. But like I said after the flush it worked great car ran tons better and the engine heat was more managable with a 180 thermostat but still gets hot once in awhile. If that light blinks theres prolly something not right.