Light spotting mid cycle?

Monica • I`m a 25 year old military wife and mother to our 5 year old son, Rylan and our sweet Maci born 7-17-15.
So twice this evening when I got to the bathroom I've had super light pink on the toilet paper. I haven't had a +OPK yet and AF was done a while ago. Does this mean O is coming soon or what? I've never had this before. I'm CD 17 expected to O on the 3rd...