Late ovulation, is there still a chance?!

I ovulate on CD 20, and my cycle is 29 days. Is it possible to be pregnant but still get my period? I'm due today for AF, however, yesterday I had a few symptoms of implantation. Only had light pink discharge once in the morning, and nothing for the rest of the day. Today I've only had some brownish spotting, but no other AF symptoms. No cramps, nothing. Is there any chance I could still be pregnant? Has anyone had these symptoms or experience this before?