Today was the first time that i wore a tampon. after removing it my period stopped & hasn't start back as yet ( 7 hours later). why? - 18 y/o, virgin

No worries: A tampon soaks up blood far more efficiently than a pad. It may take a few hours for the remaining blood to make its way out now. Tampons are so comfortable you can forget you have one. Always check at the end of a period to be sure you have removed the last one, especially if you notice any unusual odor. Use the least absorbent size/type you need for your level of bleeding.