In my experience it probably means nothing. The main chemicals which
give urine its smell are urea and some trace elements found normally
in excess in the bloodstream.
Has your urine changed colour? A colour change could mean a few
things, but changes in smell could just mean you smell differently to
other people and it smells like "egg" because thats what you liken it
to. If you're not getting enough water in your diet, urine does get
really concentrated and smelly, but if you are drinking plenty of
water, and your urine is a lighter colour and the smell is weird to
you, it could possibly be a kidney or urethral infection.
Pyelonephritis and gonorrhoea can cause urine to smell, but these are
accompanied by various other symptoms.
IF YOU ARE UNSURE PLEASE PLEASE PLEASE SEE A DOCTOR!!! THIS COULD BE
EVIDENCE OF A MUCH DEEPER MORE SERIOUS PROBLEM, OR IT COULD BE
ABSOLUTELY NOTHING. IN ANY CASE YOU NEED A PHYSICAL EXAM AND URINE
TEST TO BE SURE!!!