Test your urine and if it comes back positive, then check with your doctor.
If you are on a gluten-free diet and comply with it, make sure that you use the urine tests available at your home to check for gluten. If your tests come back with gluten contamination, check with your doctor. A stool test will be a lot better in detecting ongoing consumptions of low gluten levels.
If you find that the stool test is positive, you may need to take a close look at what is going on in your house. Try to have detailed records of what you have eaten the past couple of weeks. These records, in addition to stool testing, can help determine the sources of gluten exposure.