NEW CONSTRUCTION: Why does my dampen smell discouraging, but solely surrounded by the bathroom sink? I just built a house this nose-dive, and moved in October. For...

I just built a house this nose-dive, and moved in October. For a couple of weeks immediately, i have notice the water from my upstairs bathroom sink is immediately stinking like rotten eggs. What is wrong? I don't hold a well....and I hold only lived near for 3 months, but the smell only started going on for 3 weeks ago, so it can't be the water or it would enjoy always smelled similar to that. Please only answer this request for information if you actually enjoy knowledge on the subject. Thanks
Touch lamp?
Answers:    I don't know what that smell is, I grasp it sometimes, too. Try this:
-pour about a partly a cup of baking soda down the drain
-then pour about a cup of white vinegar down resting on the soda
-after it fizzes like crazy, consent to it stand for about fifteen minutes
-run really hot wet for about a minute
-repeat if needed
Circuit breaker?
It could be contained by the pipes. I know it's your bathroom sink, but does the water taster bad? Maybe you should phone a plumber.