A negative result can mean that you are not pregnant, you took the test too early, or you took the test wrong. Pregnancy tests vary in their sensitivity (how soon they can detect the hormone hCG), and you may not have given your body enough time to produce enough hCG hormones that will show up on the test. Also, if you let a test sit for too long (after the instructions on the box tell you), the test is invalid.

Yes! Not every woman will test positive by HPTs even though they are late for a period. If you think you are pregnant, call your health care provider and ask for a quantitative hCG to be sure. The information on this site is intended for informational purposes only and is not a substitute for the advice of a qualified healthcare professional. If you have any concerns about your health, please consult a qualified health care provider immediately.

No. The test for HIV can only tell you if you have been infected or not. Transmission of the virus does not necessarily occur every time exposure occurs. The only way for an individual to tell if he/she has been infected with HIV is to be tested. If you are unsure of your partner's status, you may want to consider talking to him/her about it and using protection (latex condoms or dental dams) to reduce your risk.

No. MyAllergyTest tests for 10 of the most common allergens. While a completely negative test result is strong evidence that you are not allergic to any of the most common allergens, it is possible that you will be allergic to a less common, or even rare, allergen.

It means that Hepatitis C antibodies were not found on the date the blood sample was taken by a laboratory in a particular blood sample.

Pregnancy & Parenting Message Boards | Chats | Topics A to Z Pregnancy & Baby Tickers | Pregnancy Calendar | Baby Names

Pregnancy can occur from intercourse that takes place during a period. This is because sperm can live in the body for up to five days, and if a woman ovulates soon after her period, then conception could take place from intercourse that occurred during her period.

Yes. The American College of Obstetrics and Gynecology, American Academy of Pediatrics, Advisory Committee on Immunization Practices and American Academy of Family Practice highly recommend that all pregnant women be routinely tested for HBsAg during an early prenatal visit, in each pregnancy. Assuming a woman is not high-risk because she was negative for HBsAg with a prior pregnancy puts the infant at risk. She may have contracted the virus since the last testing.

Scientists sometimes study Rhesus monkeys to learn more about the human anatomy because there are certain similarities between the two species. While studying Rhesus monkeys, a certain blood protein was discovered. This protein is also present in the blood of some people. Other people, however, do not have the protein. The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor. If your blood does contain the protein, your blood is said to be Rh positive (Rh+).

If you are concerned about possible pregnancy you can go directly to the OU Health Services Women's Center and request a pregnancy test. Results are available within a short time. ^ Women's Center FAQ | ^ Top

The pregnancy tests that are available at the drugstores are very sensitive. By the time a woman has missed her period, if she is pregnant, it will be positive. If she has a delayed period for another reason, it will be negative. If a woman misses two periods in a row, she should consider redoing a pregnancy test and/or seeing a doctor for a more sensitive blood test to rule out pregnancy.