This is a query we received recently, and we thought it was worth sharing the answer with our fertility blog readers.
”Last month I used one of the ultra early HCG tests on the day I expected my period, it came up positive. The following day it was negative and my period started the following day.”
Here is our answer:
Ultra early pregnancy tests can result in this finding, as they detect chemical pregnancies.One issue with ultra early tests is that be that they detect very low levels of hcg ( usually 10mIU ), and can detect what are termed ‘chemical pregnancies’. ie were implantation starts but does not proceed to a viable pregnancy.
It is estimated that this happens quite frequently, but that we are normally
unaware of this as the period may be a only a day late or not late at all.
ie the pregnancy ends very early before we even know we are pregnant. This is one of the drawbacks of ultra sensitive early pregnancy tests.