Brown discharge/ spotting from week 4 to 5

MeggieCan

Hey all-

AF was due 9/11/12.  That same day, I started with dark brown spotting.  It is about 1- 2 teaspoons/ day.  My period usually starts with dark spotting, but it turns to reddish brown on day 2.  This time around, it never increased in quantity or changed color.  On 9/17/12 I had a postive urine test.  My "pregnancy" symptoms currently are fatigue, bloating, and tender/swollen breasts.  The discharge is tapering (no need for a liner but an occasional sign with wiping).  Has anyone else had this occur?  The discharge is minimal and brown in color.  Please let me know your thoughts.  I am very nervous about this as I previously had a blighted ovum with my first pregnancy in February. 

Thank you!