Hello Doctor, 3 Weeks I Took TT Injection In A

Hello doctor,
3 weeks i took TT injection in a lab. I'm not sure does the technician used fresh syringe. From that day i got too frustrated and comfused because of HIV. I'm undergoing treatment for pemphigus vulgaris. Currently I'm taking 4 mg of methyl prednisolone daily morning and 500mg of mycophenolate mofetil daily night. I'm under this medicines for the past 8 months. I just want to know will my medicines alter my hiv test result or window period and when will i get most accurate result for HIV test. Also what type of HIV test will show me most accurate results. Thanks in advance