Implantation?

I'm not sure what's going on so here goes....

I have pcos and not regular at all. I've been taking Provera on schedule for the past few months and usually af comes a few days after the last pill.... accompanied by pms (tender boobs, cramps from hell, mood swings). Usually I cramp for a few hours and she shows up in full glory by the end of the day. I took my meds as scheduled this month, minus 2, and waited for her to show up. My boobs have been super super sore and sensitive right down to the nipple for the past 4 days and suddenly instead of cramping then starting af, I wipe and see a little amount of old brown blood... so after I shower, I put on a pad and anticipate af finally showing but no af yet. Only old brown blood when I wipe..... what does this sound like to y'all? Do y'all think I'm getting a Christmas baby this year? What did your implantation symptoms turn out to be?