My cider smells eggy but tastes fine?!!

I have only just started home brewing and am just using brew kits at the moment with a coopers fermenter kit. I have just done a cider which I followed the instructions for and on advice from forums left to ferment for a week longer than stated. It was bottled ad had 2 weeks warm then 2 weeks cold. On opening the bottles it smells very eggy, what the reason for this? And how can I prevent it in the future?

I made my first cider and bottled it last night and it smelled eggy as well but after a few seconds it had a more pleasent smell. I really hope when it is ready to drink that smell is gone or leaves shortly after the pour.

You are probably smelling hydrogen sulfide, aka rhino farts. This can be produced when cider is left on the lees for too long and when yeast are stressed. If you catch it early, you can splash rack a few times to clear it up. If you do this, make sure your sulfite levels are high enough to fight against spoilage. Unfortunately, if you don't get this until too late, you may not be able to get rid of it.

In your case, it sounds like the level is relatively low. Since it is highly volatile, you will catch a whiff of it when you first open the fermenter or a bottle of cider. As long as the concentration is low, it will probably dissipate quickly and you can enjoy your cider without out the rhino farts.