If you have irregular period or are not sure when you ovulated, you can do a urine home pregnancy test 14 days after you last had unprotected sex. However for accuracy of result, it is recommended to do the test 21 days after intercourse.
http://www.mommyedition.com/am-i-pregnant-how-early-can-i-take-a-pregnancy-test
After a miscarriage or termination, hCG may take up to 9 weeks to return to normal levels. If you test during this time, it’s impossible to know if a ‘Pregnant’ result is caused by a new pregnancy or by hCG from your previous pregnancy. In this case, we would recommend that you contact your doctor.
http://www.clearblueeasy.com/general-questions-about-pregnancy-testing.php
Occasionally, you will test positive on the first test you take and test negative on a successive test, taken a day or so later. Or, you will test positive at home and then test negative at your Obstetrician’s office. The culprit here is usually a chemical pregnancy.
http://www.mommyedition.com/am-i-pregnant-how-early-can-i-take-a-pregnancy-test
All Clearblue® Pregnancy Tests are sensitive enough to detect hCG in your urine from the day of your expected period1. Additionally, you can use Clearblue® Pregnancy Tests up to 5 days before your missed period2, although the pregnancy hormone levels in your urine may not be high enough to be detected. If you test early and you get a “Not Pregnant” test result, we recommend you test again when your period is due. Tests that allow women to test earlier than 5 days sooner than the missed period can be prone to produce false “Pregnant” results in non–pregnant women. Clearblue does not compromise on accuracy.
http://www.clearblueeasy.com/general-questions-about-pregnancy-testing.php
For those of you who want to test earlier than a urine test, you can visit your doctor for a blood pregnancy test which can help you determine if you are positive within 3-4 days after implantation or about 6-8 days after fertilization and ovulation.
http://www.mommyedition.com/am-i-pregnant-how-early-can-i-take-a-pregnancy-test
However, if done incorrectly or taken too early, the result can be inaccurate. If you get a negative result and still have symptoms of pregnancy (missed period, nausea, breast tenderness and fatigue), wait a week and take another test or contact your doctor so you can have a blood test done.
http://americanpregnancy.org/getting-pregnant/understanding-pregnancy-tests/
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.
http://americanpregnancy.org/getting-pregnant/understanding-pregnancy-tests/
Drinking too much water can affect your pregnancy test. Click To Tweet. Also, not following the test directions may affect your results. There are two basic types of pregnancy tests: one where you pee on a stick encased in plastic and one where you pee in a cup and use a dropper to place urine in a slot.
http://www.mommyedition.com/am-i-pregnant-how-early-can-i-take-a-pregnancy-test
Many questions can run through your mind every time you take an at home pregnancy test, no matter what the result turns up. Instead of worrying, let’s look at some of the most commonly asked questions about urine home pregnancy tests (HPT) and find out if you are really pregnant.
http://www.mommyedition.com/am-i-pregnant-how-early-can-i-take-a-pregnancy-test
It is recommended that you wait until you have missed a period to take a home test. A missed period is often one of the first signs of pregnancy. If you cannot wait that long to find out and you know the day you may have conceived, then the earliest you can take a test would be 14 days from possible conception.
http://americanpregnancy.org/getting-pregnant/understanding-pregnancy-tests/
how early can i take a pregnancy test
You can wait until you have missed a period to take a home test.