botched sterilization

i gave birth to a beautiful boy on march 14,01. i had my tubes tied on april 17,01 my OB doctor performed the tubal ligation, i had a follow up on apr 30. my doctor said that everything looked fine, no problem during the surgery and that she was very pleased with my recovery. a few days ago i noticed i was "late". a pregnancy test confirmed my suspicions, i seen the doctor on june 18, and she also confirmed that i was pregnant. she performed an ultrasound and was unable to find anything in my uterus,she concluded that i was either 1-2weeks pregnant, or that the pregnancy is ectopic. i have a 3 month old and a 2 year old the pregnancy is unwanted but an abortion is out of the question. we are not financially able to support another child, we would even need to purchase a larger home. the whole point of the sterilization was to avoid the possiblity of another child permanently..are the liable? can i sue for the expenses that i am going to incur? jenny va

There is a know risk that a tubal ligation may not be 100% effective. I would think that unless the surgery was shown to be really done wrong, there would be no case.