first you shouldn't be self treating yourself after a doctor gives you meds. taking more then one type of meds can interfer with the other. second reason is because you can skew any future test results. IE the one you should get now that you have a discharge. I would follow up with your doctor regarding the discharge could be relate to chlamydia, gono, or trich.
Also, some men will get a natural discharge it is not always related to an STD.
If you're getting tested you should get a urine or swab for the three listed above.
Also, in three months you should get a blood test for HSV and syphilis and HIV