If the patient has a biochemical pregnancy, there will not always be vaginal bleeding. Vaginal bleeding after a biochemical pregnancy is usually as regular as a menstrual period, and usually lasts no longer than seven days. If the patient is pregnant, the urine or blood chorionic gonadotropin test will show that she is pregnant. However, the vaginal bleeding is prolonged and heavy, and the presence of the gestational sac is not visible on ultrasound. In this case, the possibility of ectopic pregnancy or trophoblastic disease should be highly suspected. The patient should continue to monitor the blood chorionic gonadotropin, progesterone, and ultrasound for a comprehensive evaluation. If the diagnosis cannot be confirmed by these tests, the patient may choose to undergo a diagnostic curettage, in which the scraped uterine tissue is sent for examination to clarify the diagnosis.