There is a corpus luteum cyst in the left ovary. Which one of the following would be the most likely diagnosis?

A woman with menstrual cycles ranging from 4 to 6 weeks presents with vaginal bleeding following an amenorrhea of 6 weeks duration. A urine pregnancy test is positive. On vaginal exam the OS is closed. An endovaginal ultrasound scan is performed which reveals, an endometrial thickness of 12mm and an empty uterus. Adenexa are clear and there is no fluid in the pouch of Douglas. There is a corpus luteum cyst in the left ovary. Which one of the following would be the most likely diagnosis?
A. Ectopic pregnancy.
B. False positive pregnancy test result.
C. Complete abortion.
D. Incomplete abortion.
E. Complicated corpus luteal cyst