Hello and welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. If you had a tubectomy (which I m assuming is a procedure performed on your fallopian tubes to prevent pregnancy), your chance of conceiving is close to zero. That is why tubectomy is regarded as a method of permanent sterilization.Many hospitals routinely do pregnancy tests on women of reproductive age regardless of their history when they are initiating treatment of some other issue. This is usually done because many types of other physicians are uncomfortable in treating women who are pregnant, and they want to find out about the pregnancy early before you receive any other medical treatment.Irregular periods can happen to any woman and can because by hormonal irregularities. That is the reason why your doctor advised for those other tests like the TSH, FSH, LH, and others. A USG (gynecologic ultrasound) of your pelvis is simply a test to look at the shape and size of your uterus tubes and ovaries. This is sometimes used in evaluation of an irregular menstrual cycle.So in summary, the pregnancy test you received in the hospital is more due to hospital policy than your actually having a risk of pregnancy. The other tests- the hormonal tests and ultrasound (usg) are simply part of evaluation of your irregular periods. I hope I was able to adequately answer your question today, and that this information was reassuring. Let me know if I can assist you further. Best wishes, Dr. Brown