The last poster is right with bleeding its 50-50 I bled during one of my pregnancies and it ended up in a miscarriage the other I gushed bright red blood almost every day for 5 weeks and now I'm 27 weeks.
Brown blood however is old blood and isn't something to be too concerned about. Best thing to do is to contact your doctor and get checked out to make sure you aren't having a miscarriage and to have your hcg levels tested as well.
Best of luck to you please keep us informed.
Ooops, typo, I meant hcg test!
My advice is to go to the dr and have a check up. Generally they will do a quantative hgc test to check your levels and then again in about three days time. I was told that 50% of women experiencing bleeding in pregnancy go on to have healthy pregnancys to full term. I recently miscarried after spotting bright red for about 3 weeks. I was told the brown blood is a better sign. Bright red no good.
Best of luck!