I love that book. it's amazing
If its light spotting, then I think dellaK is right, sounds like ovulation bleeding...if you're trying to get pregnant, then this is the time to get at it! I will write you a caption from the book "Taking charge of your fertility" and you can see if it applies to you...
About 10% of women will notice that they occasionally have a day or two of spotting about midcycle, right around ovulation. In fact, they may even notice that the fertile cervical fluid is tinged brown, pink, or red. This is a result of spotting mixed with cervical fluid. It is considered extremely FERTILE! Its usually due to the sudden drop in estrogen that precedes ovulation and is nothing to be concerned about. If anything it is a good secondary sign to record on your chart. Its typically more common in longer cycles.
So again if you're ttc, this would be a good time for you to BD. If on the other hand it is like a full blown period...then you may want to consult a Dr. if you are concerned.
If its light spotting, then its prolly ovulation bleeding. Its too soon after your period for it to be implantation. Do you Chart you cycle with the ovulation tracker on this site
did u have sex? if yes then it could be implantation bleeding.if you are irregular then buy ovulation predictor. so u can know when u ovulate.how long ur cycle is