to answer your question...NO, the z-pack would have not interfere with your test.
follow up at 3 months
Nine weeks test is a solid sign that you did not get HIV;yet you should get what I am sure will be negative conclusive result on 12 weeks mark. And please be careful next time, HIV is not something to miss around with....also go get checked for other STDs as well
With health =)
You have to test after your 3 month window for a conculsive test result. But the good news is your test at 9 weeks is a very good indacation that your test at 3 months will be NEG.
So get tested after your 3 month window. And from now on always use condoms.