can my period start then stop a few hours later?

Hi Sarah! There's no need to be concerned. That's the typical first period you've described, I remember it very well. In my case, the first year my period was quite irregular. It can take up to two years from your first period to start having a predictable cycle. The older you are when you get your first period, the longer it can take to have a regular cycle. Your stress level, changing exercise patterns, or eating habits can also influence how regular your periods are. It's very normal, especially at first, to have periods that don't come regularly every month. For most girls, they'll eventually settle down into a regular cycle. Having your first period is a special confirmation that your female organs and hormones are working right. It is a private thing, too. Some girls tell an older sister (like you did) or mother or best friend. As for the pains and stomach aches, I didn't have them first couple of years but I do have them now, it depends on how lucky you are :-D . Hopefully these informations will help you.