What does it mean when your period starts lightly then stops completely after 24 hours?

Spotting. If your periods were regular before then suddenly turns to spotting this is not considered a normal period. It could mean that you may have a slight shedding of the lining of your uterus either from a hormonal imbalance , a polyp and occasionally something more serious. If it becomes a pattern i would recommend having it checked. You may need blood tests and an ultrasound. Check for pregnancy.