Pregnancy after tubal ligation/tubal clipping/tubal burning is rare, less than 1-2 percent cases. Also the chances of pregnancy are highest in first few months and reduce with time. After almost 10-11 years of the procedure, chances of pregnancy are less.
However, if you have missed your periods, the first thing to test for is pregnancy. If this is negative then other causes of delayed or missed periods will have to be looked at such as ectopics (can give negative urine/HCG tests, and is common after tubal burning/clipping), stress whether emotional or physical, hypothyroidism, polycystic disease of the ovary, pituitary tumors secreting prolactin, anemia and poor diet, hormonal imbalance, unexplained or sudden weight gain or weight loss. A change in routine like you had can also delay periods. You will need to consult a gynecologist for this. Take care!