Breakthrough bleeding is bleeding (either reddish or brown in color) coming from your vagina between periods. Not all bleeding is breakthrough bleeding. You could have bleeding because you landed smack on your vaginal area with the cross pole of a bike. But, most of the time, the little spotting between periods is caused by breakthrough bleeding. You're just hanging around and feeling fine and then you go to the bathroom and find that you have a small amount of reddish or brownish discharge in your underwear. CRAP! If you have pretty predictable cycles and it isn't your normal time, spotting like this can happen once in a while around the time you ovulate (about 2 weeks before your next period is due). For girls like me, with no predictability to their periods, wearing a thin pad
for a few days if the spotting continues is a good idea so that you don't have to get stains out of your underwear in case it really is your period. Keep in mind that you should talk to a healthcare professional if you're experiencing anything out of the ordinary for you.