Foul odor in urine can indicate and mean a number of different things.
Most commonly having foul urine odor can mean a Urinary Tract Infection especially if the foul urine odor smells fishy.
If you have fishy smelling urine it is likely that you have a Urinary Tract Infection and should see a doctor about it.
Some foods such as asparagus and even some medications can cause urine to have a foul smelling odor to it and if it's just the medication or food then it's nothing to worry about.
If the urine smell stops smelling foul or bad within a few days then it's likely nothing wrong with you and could just be something you ate.
Foul odors in urine can also be caused by dehydration and bladder infections.
Make sure you're getting enough fluids and water intake to stay hydrated.
I would recommend seeing a doctor about the foul odor in the urine if it does not clear up within a few days.