Am I HIV infected? Had PROTECTED with prostitute on Feb 25th.?

Had flu like symptoms (running nose and very slight fever) on March 12th. Went to doctor for checkup but did not tell him about my concern about HIV. Doctor did check but there were no swollen lymph nodes around neck. He said it might be just cold. I took some cold medicine and got better in two days. I understand the only way to be sure if to get tested. I understand I can go for antibody test after 3 months and one more test after 6 months. But I do not want to wait for 3months so I am planning to get HIV PCR (NAT) test done after 28 days. I am planning to use "STD Test Express" Service. Now here are my questions: Based on the symptoms and timelines, do you think I am infected? Second question is, do you think "STD Test Express" service is reliable? I still have 10 more days before i can go for PCR testing. Your answers will certainly bring some peace of mind. Thank you.