Most impoant investigation for ectopic pregnancy:
If TVS reveals an intrauterine gestational sac,the diagnosis of ectopic can usually be ruled out .sometimes a psuedosac may be seen in an ectopic due to bleeding produced by separation of a decidual cast.(refer pgno:159 sheila 2 nd edition)
Serial f3-hCG levels
Transvaginal USG
Progesterone measurement
Culdocentesis
General obstetrics