Had my tubes tied for 2yrs now missed 4months of my period urine blood test negative can it be a tubal pregnancy thats why it doesn't show on the test?

Hormonal Etiology. I suspect your amenorrhea is most likely hormonal involving your pituitary-hypothalamus axis or the ovary. Falling serial HCG levels are usually seen in ectopic pregnancy and its level is usually lower than that of a normal intrauterine pregnancy. See your doctor for confirmation..