was it implatation blood? confused

[mapha2]

Ladies, yesterday I had brown dischard(sorry tmi), kinda like the one you have before a period. I slept with my pad on thinking my periods visited me early. To my supprise, nothing was on my pad this morning. Went to church with only a panty linner and till now, its clean.
I'm expecting my period on the 21st so it is a week from now.
I'm confused, I keep on feeling something is coming out but nothing.
Anyone experienced this before?
Help please