Hello, Thanks for trusting us with your health concern. It is very unusual to experience a natural period along with pregnancy symptoms. This can happen with either a chemical pregnancy or with uterine anomalies like a septate or bicornuate uterus. If you have been sexually active after your previous natural period without any protection, this abnormal menstrual discharge calls for further evaluation. Brown discharge is indicative of altered blood. This can be seen with breakthrough bleeding, a missed abortion etc. A sonogram of the pelvis, preferably in the trans-vaginal route, helps to clarify. If negative, hormone imbalance should be suspected and managed accordingly. Hope this helps.