You've got a vigorous fermentation going, but otherwise you're fine. It happens a lot....pull out the arilock and clean and resanitize....then rig up a blowoff tube.
If you are using a 3 piece..do this.
You have to find a piece of long hose that will fit in the center pipe of your airlock...I had to do it in a pinch and found the the hose I had for my bottling wand almost fit....I put a small slit in it, then I soaked it in hot water for a few minutes to Soften and slid it around the tube...
I also found it is a good idea to cut, saw or break off the little criss crossing piece of plastic at the bottom of the airlock. It worked great! I used a plastic gallon applejuice jug and sanitized water to submerge the hose in.
You mean the krausen has reached the lock? You may have to rig a blow off tube. Get a 1" hose long enough to go from the mouth of your carboy into a pail of water. This will act as a giant airlock and let all the extra krausen evacuate the carboy. Seeing as how it's Sunday, you might have to improvise. Worst case scenario is that you remove your airlock, clean and sanitize it, and replace it. Repeat as necessary.