What does it smell of?
It could be an infection or dehydration, as mentioned above. It could be related to food that you've been eating, or it could be the "sugar puff" odour that many people get occasionally.
Urine can become very concentrated and take on an odor if you are not drinking enough water. This could also be a sign that you have a urinary tract infection. You can be tested for this at your doctors office or you can purchase test strips at your local drug store.
They usually have them at the pharmacy and no prescrition is required. If you do have a urinary tract infection, your doctor will prescribe a 3 day course of antibiotics. I would try drinking more water and cranberry juice and see if this helps. If not, see your doctor.