If you were getting regular cycles prior to this, you could be having either an early abortion
or an abnormal cycle due to hormonal disturbance. You can take a blood test
and consult a gynecologist for evaluation. A sonogram would be useful to assess the situation. If it is consequent to some menstrual disturbance, it can be corrected by hormone therapy
. if it is an abortion, evacuation needs to be done to arrest the bleeding. Take care.