I Am 7 Weeks Pregnant And Have Had Brown Bleeding

I am 7 weeks pregnant and have had brown bleeding for over a week. Been to the Doctor last week Monday who said I should just watch it for any new blood and do a test in a week. Which I did and the test was positive and no new blood. The brown blood seemed to have settled down, but has started up again today and it seems to be a lot heavier and not just when pee. I have a little pain in my back and lower abdomen. What is going on? Debbie