menstrual cups (good idea)???

i have recently become worried about the planet and how it is changing and i have noticed how much we throw away when on our periods.

i have seen menstrual cups and thought maybe i could try one of them to try and cut down on waste.

however i am 15 and am not sure if it will “fit”/ “go in” (sorry for tmi aha) if anyone had any advice or tips it would be very much appreciated