Having sugar in your urine is never normal. This is because the normal kidney is able to make sure that all of the blood's sugar stays in the body. The only instances when sugar makes it into the urine is when there is so much sugar in the blood that the kidney can't keep it all, or if there is something wrong with the kidney's function. The best type of physician for you to see about this is a primary care physician
such as a family doctor
or internal medicine doctor
If your doctor does not think that diabetes is the problem, then she must have already ruled it out with a blood test. This is because diabetes is the cause of sugar in the urine nearly every time it is found. If your doctor has not yet done a test for diabetes, then this is still the most likely possibility. Another possibility is a rare condition called renal glycosuria which is a genetic disease where the kidney is not able to keep as much sugar as it is supposed to.
I suggest that you schedule an appointment with your primary care physician. You can discuss what further work up will be necessary in your case. If you have note yet been tested for diabetes, then you need tested now. If you don't have diabetes, then you will need further testing for other signs of kidney problems.