Hi Amitnaunirishikesh Welcome to Health care Magic For ur Query My ans Include two parts. Part I = Laboratory investigation Query Part II = Clinical Symptoms Query ++++++++++++++++++ Part I :: Ans :: As per recent nucleic acid testing (NAT) diagnosis can be done on 16th day with p24 antigen testing and subsequently to 12 days with nucleic acid testing. ; PCR DNA 3-6 weeks Additional information About it :: see, The first antibodies detected are those directed gp41, followed by the appearance of antibodies to p24 and the gag precursor p55 There Are various tests available Like Elisa, Western Blot , HIV RNA by PCR , p24 antigen capture assay, HIV RNA by bDNA , HIV RNA by NASBA Sensitivity & Specificity Means Ability To Correctly Diagnose & Correctly Exclude HIV varies with Laboratory technique & lab level. As per Fourth Generation Laboratories Earliest Detecting Period i have already mentioned Above. HIV mainly of two types Type 1 & Type 2 virus . This is also important since Dignostic variability is bit different for each of it. Basically U Must Visit HIV Specialist Doctors Who are trendy with recent updates. So that u can be accurately diagnosed as per recent laboratory facilities available in ur locality. =============================== Part II :: Ans :: ur Symptoms may be Due to Acute HIV Syndrome . this normally occurs in 3-6 weeks. Kindly Note :: above symptoms are Not Only due to Acute HIV Syndrome ; it may be secondary to other sexually transmitted disease / other infectious disease U Must Visit ur Consultant who is Upgraded with Recent updates. So after Thorough Clinical Examination & History , He / She will guide u with appropriate Investigations. ============================ Please avoid Blood Donation untill 100% confirmation about ur symptoms ============================ Take care, Your Doubts & Query Are most welcome. Always happy to solve them. Get Well Soon. :: Dr.Vaibhav A. Deshpande