Hello Meana:
I am glad to assist you in resolving your problem. Another poster in this thread suggested correctly that air pockets form sometimes after a coolant/heating system service and can cause your safety light to come on.
I had a problem about six months ago with the "check coolant level" message coming on. I filled the coolant tank with fluid, and it would disappear after a day. There was no noticable fluid leak. A pressure check was conducted, and the technician found small holes in my lower radiator hose, and my 11-year radiator had corroded. I had my shop replace the hose, thermostat, and radiator. Now my car runs great, and the fear of my engine overheating is not longer there.
Peace,
Famous