Brown colour during 7th week can be spotting, it can be because the embyro attaching to your womb. The spotting should not last long and the colour should not be red. However, if this continue for more than a day, I will suggest that you see your doctor.
If you cannot find him, you can call his clinic to tell the nurses that you've been bleeding for more than one day and ask the nurses to find him for you. Because this can be a sign of threatened abortion.