Should I go get checked for Carbon monoxide poisoning?

The gas fireplace was on for about 10-15 minutes and the damper was closed and then i started to smell the gas and so i immedietely shut off the fireplace and opened all windows and doors. I have a slight headache now and am worried that i have carbon monoxide poisoning. should i go get it checked out or am I okay? I dont have any other symptoms except for the headache but i'm really worried. Help!