How to stop getting red while giving a class oral presentation?

i always turn bright red while giving a presentation in front of my class!! i have one coming up tomorrow then one next week! im rlly stressed/nervous about this because of my redness! i am NOT shy at all ( everyone loves me not to be cocky ) but i just get nervous ( but i always get 100% on them. i know i do good but im just scared ) so if this happens to u wat do u do to get the redness away!?? or do u have a cure to this that helps u!?? thank u sooo much! ( oh bwt im almost 15 ) :D ty :) Kaitlyn