Spotting over a week early.

I've been having discoloration and spotting since Saturday and I'm not due to start until the 17th. I'm pretty sure I ovulated on May 31st. My DH and I BDed two days after that. Could I be pregnant or is AF just being a pain and showing up early? I don't want to take a test yet since I'm not supposed to start until next week. Just curious if anyone else has had this before getting a BFP.