Is two periods in one menstrual cycle a sign of cancer?

Unlikely: Abnormal periods can be caused by several conditions, not just cancer. You are 32 yo, uterine cancer is unlikely since it is more likely to occur in older postmenapausal women. Some causes of abnormal periods are stress, birth controll pills, uterine polyps or fibroids, endometriosis...Less common are uterine or cervical cancer. If this recurrs, you should see your gynecologist for an evaluation.