I had implantation bleeding April 18,2011 it was a brownish colored discharge but only seen it when i wiped and only happened 3 times in a 24 hr. period. Unfortunately i MC May 11, 2011 with the help of an injection of Methotrexate for an incomplete MC but my Dr said the brown discharge on the 18th of april was def. implantation. sorry for the long reply lol but i hope it helps answer ur question some.