Pregnancy tests measure the amount of pregnancy hormone ,  human  chorionic gonadotrophin hCG. How early you can take a pregnancy test depends on the test you use.

Home pregnancy test

Home pregnancy test detects the presence of hCG in your urine. Some home pregnancy test are more sensitive than others. The more sensitive ones  are able to detect low levels of  hCG as early as 4 days before you miss your period or seven days after conception.

Pregnancy test sensitivity ranges  from 10mIU/ml to 40 mlU/ml. The lower the number, the more sensitive it is and the earlier it can detect pregnancy.

When you test too early in pregnancy, the amount of hCG in your urine may not be high enough for even the more sensitive pregnancy test to detect. This may give you a false negative result.

A good time to use a home pregnancy test is around the time your period will be due. If you get a negative result but still don’t get your period, testa again 3 days later. If you are indeed pregnant, the  your hormonal level will have picked up to be detected by the test.

Blood pregnancy test

A blood pregnancy test can also detect hCG . It is more sensitive than urine test and can detect pregnancy  about 6 to 8 days after ovulation. You should know that you will not be offered a blood test until after your period is due.
 
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