Getting a blow job is not a risk and a test is not needed.
Fourth generation tests that look for the antigen and antibodies are conclusive after 28 days (CDC says 28-45)
P24 antigen is part of the HIV itself, and antibodies are the response the body makes to get rid of the antigens. So therefore antigens are detectable until the antibodies clear it out, at which time the antibodies would be detectable.
Most experts says 28 days is conclusive, the CDC says anytime after 45 days.
Regardless you don’t need a test if this was your only exposure.
The 4th Generation is conclusive at 28 days (4weeks) after your sexual encounter.
If u still decided to test more.the result will not changed.
Believe your DUO test result.