How do you know if are pregnant when your test is negative and have no period?

A negative pregnancy test usually means that you are not pregnant. However, there are some cases in which a pregnancy test may be negative even if you are pregnant. There are a few possible reasons why you may have a negative pregnancy test and no period.

* You are too early in your pregnancy. Pregnancy tests work by detecting the presence of human chorionic gonadotropin (hCG) in your urine. hCG is a hormone that is produced by the placenta after an embryo implants in the uterus. It typically takes a few days for hCG levels to rise to a detectable level, so if you take a pregnancy test too early, it may be negative even if you are pregnant.

* You have an ectopic pregnancy. An ectopic pregnancy occurs when the fertilized egg implants outside the uterus, such as in the fallopian tube. Ectopic pregnancies can be dangerous and require medical treatment. If you have an ectopic pregnancy, you may have a negative pregnancy test because the hCG levels in your urine may not be high enough to be detected.

* You have a miscarriage. A miscarriage is the loss of a pregnancy before 20 weeks of gestation. If you have a miscarriage, you may have a negative pregnancy test because the hCG levels in your urine will drop after the pregnancy ends.

* You are taking certain medications. Some medications, such as birth control pills and chemotherapy drugs, can interfere with pregnancy tests and cause a false negative result.

* You have a medical condition. Some medical conditions, such as thyroid problems and kidney disease, can affect pregnancy test results and cause a false negative result.

If you have a negative pregnancy test but you have missed your period, it is important to see a doctor to rule out pregnancy and other possible causes.