If you mean, how long should you wait until taking the hiv test, then the answer is after 3 months. Getting tested earlier than 3 months may result in unclear or inaccurate results.

A standard hiv test, which is the least expensive, could be taken at the end of the 3 month period, because hiv antibodies are present in the blood which may show a hiv blood from 4 to 12 weeks. A standard hiv test looks for hiv antibodies.

A pcr dna test also expanded as the polymerise chain reaction dna test, is more expensive test, which looks for the presence of the actual virus dna strains in the blood. This can be done even immediate to a infection, for the hiv virus multiplies extremely fast.

i got tested after 5 and 10 weeks , yhe result was negative by elisa , and after 13 weeks i dine PCR test also negatif, should i di more tests or i'm definitely nrgatif?

I think you should celebrate and take the tests results as they are.

After having Un-protected Sex, I had undergone HIV DNA PCR test for 3 times in 13 months (i.e., after every 4 months alternatly). is it ok ??

yes