Let your Dr. know however, it's probably something very common called "implantation bleeding". Google it for more info.
Brown discharge is blood. It is fairly common for women to have some bleeding in early pregnancy. About 30% will, with about half of those having an otherwise normal healthy pregnancy.
If it's just spotting (whether it's brown, red, pink) let your Dr. know at your next appointment. If it gets heavier, make sure you call your Dr. If you are in second or third trimester, you should also contact your Dr.
All the best to you. Chances are this is fine.