Hi,

There are a couple of possibilities that come to mind. The first is that you received treatment, it worked, and you are clear from infection. The second is that one of the tests is giving you a false reading (known as a false positive or false negative). A false positive result means you have been told you have the infection - but you don't, a false negative means you have been told you are clear - but you arn't.

If for some reason you didn't receive treatment after the first test, I think the next logical step would be to go back to the doctor and talk to them about why you have different test results and whether you should undertake a retest to make sure. Dr Charlotte Grayson provides some useful tips about testing in this Sharepost.