I am having lower abdominal cramps, fatigue, nausea, headaches and breast tenderness for about a week now, cauterized 4yrs could i be pregnant?

Yes: I'm guessing you are referring to having a tubal ligation with cauteriation. Tubal ligation is not perfect and the failure rate increases as time increases. If you are having pregnancy-like symptoms, you could be pregnant. Please get a pregnancy test asap, because if you are pregnant, your past tubal ligation puts you at risk for having an ectopic pregnancy which could be an emergency.