If your friends are making fun of you they are not friends.
Smile in a superior kind of way and say no - no bleeding for me yet - ha ha.
No embaressing stains, no bloody sheets in the morning, no chance a boy will find my pads in my school bag, no uncomfortable pads to deal with under my clothes, no cramps, no mood swings... do I need to go on?
Don't complain about not getting your period yet; celebrate.
Your period will start one day and you will get it regularly for years until you are around 50! Don't be in a hurry to start