Generally around six weeks after a missed period, an ectopic pregnancy can be detected through an ultrasound examination. For women with regular menstrual cycles, if menstruation is delayed by a week and a pregnancy test shows a positive result, it indicates pregnancy. At this time, it is necessary to visit the hospital for an ultrasound to ascertain the implantation site of the gestational sac. In the case of an ectopic pregnancy, it is normal that no gestational sac is visible within the uterine cavity during an ultrasound. The ultrasound might reveal irregular echo areas in the adnexal area, which includes the fallopian tubes or ovaries, possibly indicating thickened fallopian tubes or enlarged ovaries. At this point, one should be vigilant about the possibility of an ectopic pregnancy and seek timely treatment.