Thanks for the query!
There are so many causes other than pregnancy which may cause delayed period.
The most common reasons are hormonal imbalance, thyroid disorder, stress, excessive weight changes, infection, PCOD, polyps and fibroid.
If the pregnancy test is negative after 8 days of a missed period, then the chances of pregnancy are very less.
You should consult a Gynecologist and get yourself examined and investigated to rule out the above-mentioned causes.
Hope it was useful.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.