Vaginal bleeding between periods is one symptom of abnormal uterine bleeding. Having extremely heavy bleeding during your period can also be considered abnormal uterine bleeding. Very heavy bleeding during a period and/or bleeding that lasts more than 7 days is called menorrhagia.
The tests your doctor orders may depend on your age. If you could be pregnant, your doctor may order a pregnancy test. If your bleeding is heavy, in addition to other tests, your doctor may want to check your blood count to make sure you don’t have a low blood count from the blood loss. This could lead to iron deficiency and anemia.

An ultrasound exam of your pelvic area shows both the uterus and the ovaries. It may also show the cause of your bleeding.