Is it safe to use a tampon if you started your period yet?

No, it is not safe to use a tampon if you have not yet started your period. Tampons are inserted into the vagina, and before you have started your period, the hymen is still intact. Inserting a tampon before the hymen has broken can be painful and can also damage the hymen. It is best to wait until your period has started before using tampons.