Early bleeding possible pregnancy

Patient: Hi i recentlty missed a few of my pills from my pack. I started bleeding a week early, however not a usual period. It was brown in colour and very light. I have taken 3 tests which have all come back negative. I have been sick and also had diahorea aswell as feeling tired all the time. I have been to my docters who told me since i have already taken a test they would not need to and if i was the same next month to then go back to them. I have also had stomach pains. Could i still be pregnant?