Hey desi, I hear ya on feeling like you're walking too much. I feel that way.
Like a lot of the ladies in here, I work in education and I'm always standing or walking around the building, up and down stairs, etc. I'm so tired by the end of the day! And there's really nowhere private where I can lock myself away at any point.
Welcome new ladies! It's funny to think you just found out you're pregnant when I've known for over two weeks that seemed so long!
Anyways, from what I've read on here from tons of people brown blood is totally normal and old blood. There's no reason to worry unless it's red.