A somewhat insensitive term for when conception and implantation have occurred, producing a positive pregnancy test, but without sign of a gestational sac appearing on transvaginal ultrasound; in other words, a subclinical miscarriage or a menstrual miscarriage. See also: miscarriage

Early embryo development begins but does not become established, so pregnancy tests are positive at first but become negative. This is usually followed by a late period.

Is a positive hCG blood test with no evidence of a gestation sac on Ultrasound.