*TMI* Spotting/BTB on Third Pack! opinions?!

hey guys! so I was on my 3rd pack of BCP(Aviane28) and on the 2nd week, started having light discharge which I assume I was spotting. this is odd since for the first two packs, my period came right on the placebo week like it's supposed to, and never had any bleeding in between.

it's the 7th day(of spotting) today and I still have dark brown discharge down there. I've searched on the forum, and everyone seems to think its likely pregnancy? my af is next week. what do you guys think? we've always used condom and check it afterwards - no breakage and I've always taken my pills on time (and three or so times 15 mins late)

. what's the likelihood of pregnancy, or is it just my body getting use to the BCP? anyone on Aviane28? thanks everyone!