Very normal! It's old blood. The same thing happen to me when I was almost 8 weeks. It went on for 4 days and stopped. Don't worry!
I went through the same thing its normal long as its not light red!!!
That scared me too! But the doctor said it is normal , thank goodness! If it is bright red or if it has a smell, you better ask your doctor.
Brown is typically old blood nothing to worry about :) if it becomes bright red or you have clots go to the er