If you are anxiously awaiting confirmation that you are indeed pregnant, any small change in the way you feel might find you running out to buy a home pregnancy test. Before you get carried away, take some time to investigate your symptoms and make sure they aren’t indicators of a different kind.
For most women, the first signs of pregnancy are a missed period, breast fullness, breast tenderness, nausea, frequent headaches, and fatigue. While some symptoms of pregnancy can occur as soon as one week after conception, the same symptoms can also indicate other non-pregnancy related conditions. For example, some women experience breast tenderness right before their menstrual period. Even if you experience several symptoms characteristic of pregnancy, this doesn't mean that you are necessarily pregnant. You may find, for instance, that your nausea, fatigue, and frequent headaches are signs of the flu, rather than pregnancy. There is a difference between a pregnancy symptom (which may indicate pregnancy, but might also indicate illness or infection) and the more definitive pregnancy sign (such as a positive blood test for pregnancy or a detectable fetal heartbeat).
Once you have determined that your symptoms are not caused by illness, you may want to use a home pregnancy test to confirm that you are pregnant. Home pregnancy tests measure the amount of a hormone called human chorionic gonadotropin (HCG) in the urine. HCG levels are low in women who are not pregnant, and begin to increase within the first few weeks of conception. Although most tests claim to be able to detect pregnancy as soon as the first day of your missed period, you will obtain a more accurate result by waiting to take the test until 7 days after the day you expected your period to occur.
Although home pregnancy test results are generally accurate, they aren't as definitive as the blood test for pregnancy that your doctor can administer. Home pregnancy tests can sometimes produce false negative and false positive results. Blood tests remain the most effective method of detecting pregnancy. You should ask your doctor to perform a blood test a week after your missed period if you suspect you may be pregnant despite a negative home pregnancy test result, or if you want positive confirmation as to whether you are pregnant or not.