Thanks for the query.
I understand your concern.
Little bit of irregularity in periods can occur due to many causes like lifestyle modifications, weight changes, stress and strain etc.
As your partner underwent tubectomy and as your urine pregnancy test kit gave negative results, the possibility of pregnancy is less.
As your menstrual period is eight days delayed, now you better consult your doctor and take tablets to induce withdrawal bleeding.
If irregularity in menstrual cycles persist, you may need through evaluation to find out the possible cause of the problem and treatment has to be taken accordingly.
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.