(( VaginaPagina ))

I think it depends on how much blood. If it was just a little it should be normal. The occasional spotting is normal. But if it was a significant amount of blood, it could have been something more; maybe a hormone fluctuation or the signs of a cyst or fibroid. I would suggest you wait until you have your period and see if anything else is abnormal (heavier or lighter bleeding than usual, worse than average cramping or PMS, discharge, or anything else that's strange for your body). If everything seems typical, then it was almost certainly nothing (at least nothing that can't wait for your next physical, where you might bring it up if you are still worried). If something is unusual about your period, I would suggest an appointment then.