Hi Anon and thanks for your question.
If there are menstrual changes following tubal ligation, this is most likely due to the impact of aging or stopping birth control pills, but not because of the surgery.
Are you near the age when women start perimenopause, the period of time before menopause causes the complete end of periods?
If not, and you think you are pregnant, it would be important to take a pregnancy test. If a tubal ligation fails and you become pregnant, you have an increased risk of having an ectopic pregnancy. Ectopic pregnancies can occur years after the tubal ligation and are most likely to occur three or more years after the procedure. This can be a life-threatening condition and needs immediate medical attention.
Hope that helps,