Pregnancy Test

To determine whether a woman is pregnant.

There are no risks involved beyond an incorrect result.

All pregnancy tests work by detecting a certain hormone in the urine or blood that is only there when a woman is pregnant. This hormone is called human chorionic gonadotropin, or hCG. It is also called the pregnancy hormone.

hCG is made when a fertilized egg implants in the uterus. This usually happens about six days after the egg and sperm merge. But studies show that in up to 10 per cent of women, implantation does not occur until much later, after the first day of the missed period. The amount of hCG rapidly builds up in your body with each passing day you are pregnant.

There are many different types of home pregnancy tests (HPTs). Most drugstores sell HPTs over the counter. They are inexpensive. But the cost depends on the brand and how many tests come in the box.

Most HPTs work in a similar way. Many instruct the user to hold a stick in the urine stream. Others involve collecting urine in a cup and then dipping the stick into it. At least one brand tells the woman to collect urine in a cup and then use a dropper to put a few drops of the urine into a special container. Then the woman needs to wait a few minutes. Different brands instruct the woman to wait different amounts of time. Once the time has passed, the user should inspect the “result window.” If a line or plus symbol appears, you are pregnant. It does not matter how faint the line is. A line, whether bold or faint, means the result is positive. New digital tests show the words “pregnant” or “not pregnant.”

Most tests also have a “control indicator” in the result window. This line or symbol shows whether the test is working properly. If the control indicator does not appear, the test is not working properly. You should not rely on any results from an HPT that may be faulty.

Most brands tell users to repeat the test in a few days, no matter what the results. One negative result (especially soon after a missed period) does not always mean you are not pregnant. All HPTs come with written instructions. Most tests also have toll-free phone numbers to call in case of questions about use or results.

Many home pregnancy tests (HPTs) claim to be 99 per cent accurate on the first day of your missed period. But research suggests that most HPTs do not always spot pregnancy that early. And when they do, the results are often so faint they are misunderstood. If you can wait one week after your missed period, most HPTs will give you an accurate answer. Ask your doctor for a more sensitive test if you need to know earlier.