Hello, As you have gotten two consecutive negative pregnancy tests, then possibility of being pregnant is extremely low. At the onset, late period itself can cause light spotting or brown discharge. It could be due to hormonal imbalance, over weight, mental stress, emotional upset, pelvic or vaginal infection etc. If you don t get your period properly within 7 days, I suggest to undergo one pelvic ultrasound scan and hormone test to confirm diagnosis. You may require hormonal pill to regularize period. Kindly, consult with your gynecologist and take advice accordingly. You should control body wt, avoid stress, take healthy low carbohydrate diet with avoidance of fatty food and sleep properly. Be well.