Tone an Andy thank you for your input!

I called my dealer's service department this morning and the tech said that it is most likely because the gas cap was not tightened enough or the plastic "strap" that is attached to the gas cap was caught when I was tightening the cap.

Last time I filled up was about 4 days ago and no light came up. He asked me if I had about half of tank left and I had exactly half-tank left when the light came on so he said that the reading is taken by the system at certain intervals and half-tank level is one of them. He suggested to fill up again to full tank, then make sure the cap is well tightened, and then the next time the reading is taken the light should go away. I did that and so far the light was still there while I drove to work. We'll see if it goes away and if it doesn't I'll try disconnecting the battery.

Hopefully I am worrying for nothing. Thanks again everyone!