If done correctly, the home pregnancy test is extremely sensitive. In the vast majority of cases, if the test is negative, then you aren't pregnant. There are two important exceptions to this rule. While the tests are fairly easy to use, some women use them incorrectly lowering their accuracy. If you plan on taking another one. Make sure to quickly glance through the directions prior to using it. The second exception is if you took the test too early. It takes between 1 and 2 weeks after conception for the pregnancy test to become positive. Thus, if you took the test too early, it may have read negative when you really were pregnant.
is very accurate at detecting pregnancies in the uterus, but they can miss pregnancies outside the uterus (also known as ectopic pregnancies). In addition, they won't detect a pregnancy that is very early because the embryo may not be big enough. Thus, ultrasound is not used as the first test for pregnancy.
I suggest that you schedule an appointment with your OBGYN. He or she can administer a urine pregnancy test and tell you for sure whether or not you are pregnant. If you are not pregnant, then your doctor
can look into why you have missed your period for 2 weeks.