Is 4th gen combo ab/ag hiv test really conclusive 6 weeks post exposure? i keep seeing different opinions from different docs here in healthtap, some say 6 weeks, some say 12 weeks, and some even say rna test after 6 months. which is it?

It should be conclusive by 6 weeks. By 7 weeks, all infected people should have p24 antigen and/or HIV antibodies in their blood but the test may fail to detect them (false negative result) because no medical test has 100% sensitivity. However, if test remains negative with a second time then the sensitivity may be close to 100%. If you're asymptomatic after a suspected exposure then you are fine.

Duplicate question, see previous reply. But do not expect 100% consistent replies. If you remain concerned, go to authoritative sources like CDC, which endorses 45 days (a little over 6 weeks) for a conclusive negative test result. No point in repeatedly asking the same question; the answer won't change!