Worried...

[actingblood15.livejournal.com]

hello, I'm a bit worried about something. I've been on the pill since March and this is the first month I've ever experienced spotting. I started taking this months cycle of 21 pills on Sunday right when my period was ending. And it went away until Friday when I started spotting a dark brown substance that I'm assuming to be old blood. Is this normal? In reference to my period I normally start on a Wednesday but instead started on a Thursday. Could this have altered the amount of blood my body was able to shed in the time I wasn't taking my pill. Could me starting the pill that Sunday have disrupted it and now I'm spotting the last bit of my period blood? I'm sorry if this is a confusing entry. Any help or advice or personal recollections any of you could tell me would be very much appreciated. Thank you
-Kendra