Ureaplasma is a sexually transmitted disease that is often asymptomatic.
Most clinics and doctors don't test for Ureaplasma because it is a less common STD than others, and often not really considered sexually transmitted disease. All sexually active persons get Ureaplasma at one time or another and regular tests would often find people carrying the organism, which does not mean they have a disease.
Ureaplasma tends to be looked at as part of the normal bacteria that normal people carry. Since it lives in the genitals, the organism can be transmitted sexually. Some Ureplasma strains may be more likely to cause real disease than others. Even with the "bad" strains, actual disease only happens in men.
If you suspect you are not well, or would like to get confirmation that in fact you are well, you have a number of options to test your urine and get the right diagnosis. The simplest test you can do is the over the counter urine dipstick test that can be bought at local pharmacies. These tests will tell you whether you have any number of chemical imbalances in your system.
The over the counter test will show you chemical results, but to get the right diagnosis, you would be well advised to seek help from a qualified healthcare professional. The healthcare professional can send you to more tests, or provide a diagnosis and suggest treatment options.