Hello, Your symptoms are suggestive of a hormone imbalance. The dark color of the bleeding indicates venous and old blood. The fact that it occurred twice in the same cycle corresponding to the ovulation period and the onset of the menstrual period shows that there has been a breakthrough. If you are sexually active, the possibility of conception also should be borne in mind. Please get a sonogram of the pelvis, preferably in the trans-vaginal route after a proper clinical evaluation by an expert to clarify. Hormone supplements may be needed once pregnancy is excluded. Maintain a healthy weight and a healthy diet. Hope this helps.