The major symptoms of ectopic pregnancy are abdominal pain on one side of the body, vaginal bleeding that is dark in color, and shock in some cases. In many abdominal pregnancies there is one missed or late period, and then normal menses after this. Since there is not a uterine implantation, the progesterone levels do not calm the uterus. This causes sloughing of the stratum functionalis of the endometrium of the uterus. The female reproductive tract begins its normal cycling of estrogen and progesterone creating a menses.