Beta hemolytic bacteria in blood agar.

In Microbiology class we took urine samples and mine was used to determine the type of bacteria in the urine. We used a centrifuge to consolidate the bacteria and poured the urine sample which we did not need out. After inoculating the bacteria on to a gram positive, and gram negative indicative agar, we also inoculated the bacteria on to a blood agar and allowed it to incubate for 48hrs. Before we looked at the urine samples the teacher explained if you have beta hemolytic bacteria in your blood agar, you will probably be alone for the rest of your life. He came through and my blood agar showed beta hemolytic bacteria. This was incredibly humiliating and degrading. He stated I "needed to go get this taken care of in front of the class. I do not have any known STD's and went and immediately spent $300 dollars on an emergency STD test. what do such results actually mean?