There is a slight chance I may be pregnant, and I am now having bleeding and am not sure what it may be. Conception would have been 18 days ago. My period normally starts out very heavy flow and dark red/brownish in color. Yesterday I started bleeding, but it started out light pink and a very light flow, instead of the usual dark stcky beginning flow. It is still a light flow today & bright red in color, there are also some blood clumps. I'm not sure what to make of this, could it just be an irregular period or is implantation a higher possibility? Thanks.