DO you have natural gas? They put an additive in natural gas that smells like rotten eggs, so it can mimic a sewer gas smell. If you have natural gas, you may want to call the gas company immediately, and tell them that you have a suspicious smell in the kitchen. Around here, they come out for free, and bring a meter that can detect the gas.
Someone may have been working on utility supply lines somewhere near your home, and gas could now be leaking in somewhere, so it may still be gas even if you dont use it. Or you could have cracked a line if you or someone else recently moved your gas range to clean around it.
Just a thought, but you cant be too careful, especially if your house can blow up.
We had that happen around here a few years ago. The gas company was working on a gas line, and they caused a leak without knowing it. The gas travelled along the conduits and leaked into the first home that it came to. The house exploded in the middle of the night, killing everyone inside.