Do blood tests tests that come back as normal rule out chances of having hiv.?

No,

You will need to take one of the following test.

In most cases the EIA (enzyme immunoassay), used on blood drawn from a vein, is the most common screening test used to look for antibodies to HIV. A positive (reactive) EIA must be used with a follow-up (confirmatory) test such as the Western blot to make a positive diagnosis. There are EIA tests that use other body fluids to look for antibodies to HIV. These include:

Oral Fluid Tests 鈥?use oral fluid (not saliva) that is collected from the mouth using a special collection device. This is an EIA antibody test similar to the standard blood EIA test. A follow-up confirmatory Western Blot uses the same oral fluid sample.
Urine Tests 鈥?use urine instead of blood. The sensitivity and specificity (accuracy) are somewhat less than that of the blood and oral fluid tests. This is also an EIA antibody test similar to blood EIA tests and requires a follow-up confirmatory Western Blot using the same urine sample.
Rapid Tests:

A rapid test is a screening test that produces very quick results, in approximately 20 minutes. Rapid tests use blood from a vein or from a finger stick, or oral fluid to look for the presence of antibodies to HIV. As is true for all screening tests, a reactive rapid HIV test result must be confirmed with a follow-up confirmatory test before a final diagnosis of infection can be made. These tests have similar accuracy rates as traditional EIA screening tests. Please visit the rapid HIV testing section for details.

Home Testing Kits:

Consumer-controlled test kits (popularly known as "home testing kits") were first licensed in 1997. Although home HIV tests are sometimes advertised through the Internet, currently only the Home Access HIV-1 Test System is approved by the Food and Drug Administration. (The accuracy of other home test kits cannot be verified). The Home Access HIV-1 Test System can be found at most local drug stores. It is not a true home test, but a home collection kit. The testing procedure involves pricking a finger with a special device, placing drops of blood on a specially treated card, and then mailing the card in to be tested at a licensed laboratory. Customers are given an identification number to use when phoning in for the results. Callers may speak to a counselor before taking the test, while waiting for the test result, and when the results are given. All individuals receiving a positive test result are provided referrals for a follow-up confirmatory test, as well as information and resources on treatment and support services.

you can go to this web site and find a place to take this test.
www.hivtest.org

Doctor's test for HIV using the ELISA test which stands for enzyme immunoassay. The local planned parenthood tests your blood at least three times before determining whether or not you HIV. This test can be very expensive so it is unlikely they will test for HIV without you requesting it.

No HIV can take up to 3 months to detect on a blood test so if you think you have been infected, obviously go for a test and your doctor should request to check you again in 3 months time.