If you had an ectopic pregnancy, you would probably have noticed one-sided pelvic or abdominal pain by now. What made your doctor think you have a tubal pregnancy?
Did your doctor say anything about symptoms that would indicate a potential tubal pregnancy? Some symptoms of tubal pregnancy are vaginal bleeding (including spotting), missed period, breast tenderness, nausea, and occasionally pain in the shoulder. It's basically the same symptoms as a normal pregnancy, with a few exceptions. Also, have you taken any home pregnancy tests? Sometimes ectopic pregnancies will not give a positive result on the home tests.
I'm not trying to frighten you or anything - in all honesty, I seriously seriously doubt you have an ectopic pregnancy going on. It seems quite irritating that your doctor would brush off a condition such as ectopic pregnancy (which can be fatal if the tube ruptures).